Cedar Point advice

Both would be very good days to go with Friday being slightly more crowded. You shouldn't need Fastlane on either day. If you are staying onsite/or have a Cedar Fair platinum pass take advantage of the 1-hour early admission but you might be just fine without it.
Your highlight rides should be:
Maverick - My personal #1 steel coaster
Millenium Force
Top Thrill Dragster
Magnum XL-200 - My personal #2 steel coaster
Raptor
Gatekeeper
Valravn
Skyhawk
MaxAir
Given these are early June days you shouldn't have a problem getting on all these rides... and them some. I was able to do all of that and more on a Halloweekends Sunday without fastlane, and these days will be much less crowded.

Argh.h.h.h.! Ben, yer killing me here! I have to work both days- it'd be great to get to meet you. I've always enjoyed your articles on TPI. Oh, well..
1. Yes, you can get the highlights in one day, and that early in the season should not be a problem. Plus flying solo means that you don't have to wait for anyone who just HAS to stop at the basketball hoops games (which I hate). Jaiden's list is pretty good, but if you like classic wooden out-and-back coasters don't miss Blue Streak, the oldest coaster in the park (52 years old, I think. A bit rough, but wonderful airtime. Also, don't miss Cedar Downs, one of the last operating Racing Derbys in the world. It looks like a big carousel, but it's so much more. One more is the Sky Ride. There aren't many of them left.

2.Yes, it will be more crowded than this week, but Cedar Point is HUGE, and even with a massive crowd it doesn't often feel crowded because there is so much space. Luminosity is different every year, and it can be a neat experience, but I would probably not plan on waiting for it and staying for the whole show. Catch part of it if you can, but don't plan your vacation around it. A Disney castle show it ain't.

3.Staying on site can be convenient, and the early entry saves time on getting to ride some of the most popular rides before the crowds get in. A stay at the Breakers is memorable- it's one of the largest and oldest hotels on the Great Lakes, and all the rooms have been completely refurbished. Plus it's nice if you want to go back to your room to change if you feel a bit sweaty from Ohio humidity. It is expensive, but since you'll be driving and will have a car, staying there will get your parking fee refunded at the front desk. Yes, you have to pay when you get to the parking lot, but keep your receipt and they'll refund it. The other hotels on Cedar Point are not worth it for just one person. The completely refurbished Cedar Point Express hotel is less expensive, but it is not on Cedar Point itself. You have to drive and park, and they don't refund your parking, but you do get early entry and discount entry tickets. Check out their website for all the details and prices. If you have the money and want the convenience and appreciate the historic atmosphere, stay at the Breakers Hotel. If you want a nice, cheaper but still nice hotel without the convenience of direct access to the park, stay at CP Express.

4. I don't think you need Fast Lane unless you insist on riding the same coaster over and over, plus Fast Lane doesn't always get you all that close to the front of the line. Some coasters have it but rarely need it. I would really doubt you would find it worth the price.

5. Cedar Point is not known for being a foodie destination, but there are some new places this year that have potential. MELT is a new gourmet grilled cheese place that has other locations in the Cleveland area and is really popular there. Famous Dave's is a bar-b-q place with a full service restaurant in the Marina, just outside the Valravn/Marina entrance gate (Cedar Point is so large it has four entrance gates!), and this year they're opening a counter service place with limited menu inside the park. Great ribs and brisket! Also, try the Toft's ice cream at their ice cream parlor near the front gate/Skyride station. My great friends the Rao family visit often and are addicted to the elephant ears pastries served at several locations throughout the park- pizza-sized pastries covered with butter and cinnamon sugar. Personally, I love the perch sandwiches you can get near the Gatekeeper station, but it is one of those fish things that you either love or hate. If you like fish, try it, but be sure they don't drown it in Tartar sauce. BTW, the Raos hate the perch as much as they love the elephant ear.

Don't miss a walk down Frontier Trail, which leads from Millennium Force to Frontier Town. Not quite as historic as it used to be, but still has lots of themed charm, original log cabins, some working craft shops, and plenty of shade on a hot day. Don't rush down it- stroll and check it out.

I'm looking forward to hearing how you like Cedar Point. Wear comfortable walking shoes- seriously, first time visitors have no idea how big it is. 364 acres, and since it was not originally planned as an amusement park and is literally in the middle of Lake Erie its layout is kind of unusual for a major park, so be ready to walk a lot. Hint- if you don't stay in the Breakers and have to use one of their parking lots, decide where you want to park ahead of time. You can use the Cedar Point Shores (formerly Soak City) parking lot and use a gate there and already be at the back of the park. Lots of people start at the front and work their way back- if you start at the back and work forward you might miss some of the crowds. Frankly, though, this time of the year should not be too bad. You're an experience TPIer- check out the park map and figure out what works best for you.

Have a great time discovering Cedar Point, America's Rockin' Roller Coast- Ride On! (sorry, habit from hearing it so much when I go)

I would echo the thought of staying at a CP resort. The Breakers Express should be back open after its rehab. Its a nice, simple hotel that will not break the bank.

However, if you are going for one day, I would say shoot for the stars and stay at Hotel Breakers. Its right on the Beach. It is the Grand Floridian of CP.

I got the regular "jump the line pass" and was pretty much able to get most stuff done in a day. Going the hour early really helps! I would recommend Maverick if you want to ride multiple times!

James has pretty much covered everything, but I'll add a couple thoughts of my own as well.

1. One day should be plenty of time to do all the must-do attractions. You won't be able to do every ride, and you probably won't have time for any re-rides, but as long as you move at a reasonable pace it shouldn't be too difficult to see everything. I'd prioritize the rides Jaiden and James have recommended, and also add Wicked Twister and Power Tower to that list.

2. My visits have been in July and August, so I'm not 100% sure what crowds are like in early June. However, if it is anything like other seasonal parks you'll probably see some of the lightest crowds of the season. Unless you want to see Luminosity, I'd probably opt for going on Thursday.

3. If you don't have a Cedar Fair Platinum Pass, it is worth it to stay onsite for early entry. If you do, save money and stay somewhere cheaper. I'd probably opt for CP Express for a one-day trip as it is cheaper and you probably won't be spending much time at the hotel.

4. I doubt you'll need Fast Lane unless you want multiple rides on every major attraction. On my most recent visit (July weekday in 2014), I didn't arrive until 2 P.M. on my first day and was still able to do all but one of the coasters without one (granted, I skipped all non-coasters that day). It doesn't hurt to budget for it in advance, but don't buy it until you get there and determine you need it to do everything.

5. While it may be tempting to run from ride to ride, don't rush around the park...take your time and enjoy it. The front part of the park is pretty bland theme-wise, but the back half is nice for a regional park.

I'm not sure what weather is like in June, but be prepared for anything. I've seen a day go from sunny, to raining, to sunny again in a couple hours. Note that Cedar Point will close most major attractions when it is raining, but rides usually reopen shortly afterward and lines are usually significantly less.

Try to avoid backtracking as much as possible. Cedar Point is big, so you will wear yourself out if you don't go sequentially. I recommend trying to get a couple rides each on Millennium Force and Maverick during early entry, then going clockwise around the rest of the park from there. Save the rides at the front for later in the day.

I think that's about all I've got. Have a great time at the park...it is one of the best out there.

I would also say that some of the gems of CP aren't necessarily the coasters (though they are great!). There is a racing carouse which is loads of fun and the surprisingly interesting train ride. You get to visit Boneville which might be one of the oddest things in the entire park. I would also recommend doing a glass works class. It is something different and loads of fun. You can make a glass coin which is kind of neat and not too expensive.

Everyone's recommendations are spot on.
If you have time (and if it is still there), there's a great museum at the back of the park near Maverick that gives you a lot do great history on the park.

The Town Hall Museum! Lots of great history about the second oldest amusement park in the country...and it's air conditioned. Thanks, Scottland!

Thank you guys! Wonderful advice all, very much appreciate you taking the time to offer help.

I'm considering staying in a cheap off-site the night before, and booking Breakers for the night of my park visit day. (So I can take an afternoon break etc.) I can't find any information about how early entry actually works though - does anyone know if I'd be able to do this, if I hadn't yet checked in?

James - would have been great to say hello. Alas, I'll settle for a re-read of your history article instead!

I don't know if you can get the early entry before checking in. I think you get a pass of some kind at check-in to present at any gate, and they have a line/queue for early entrance. You could contact the hotel or reservations directly and ask. One other option might be to check out of your off-site hotel early and go to the Breakers early. Your room might not be ready, but they might let you check in and get your pass, refund parking, etc. I'd be sure to contact the hotel directly ahead of time to see if they can do that. You might be stuck with them saying that you can only use the early entry the next morning, the day you check out. I don't know for sure, but plan ahead.

I hope you find the history article interesting. Maybe your next visit to the Point we can meet up.

I bit the bullet and booked for Breakers. Thanks for the encouragement!

I found out that you can indeed use the early entry on your day of check-in - but only if you've purchase the tickets as part of your hotel package. Tickets are available to collect from 8am from the hotel on day of check in.

That's good to know. From the Breakers you have direct access to two of Cedar Point's Gates. The "Beach Gate" enters the park right next to Windseeker, so if you want to hit the front of the park use that gate. The "Resorts Gate" enters next to (and underneath) Magnum-XL 200, so use it if you want to go to the back of the park. Be sure to take a stroll on the boardwalk along the beach. Cedar Point started as a beach resort (and beer garden) and the view of the Breakers from the beach and boardwalk is the most historic view you'll get of the original sections of the hotel, the Rotunda.

To get to the Breakers Hotel, take the Causeway and get into the far left lane. Just tell the person you want to go to the Breakers- you'll have to pay the parking lot fee, but take your receipt with you to the hotel and they should refund it to you. They'll ask you if you know how to get there- take the drive along the side of the park (you'll see the Blue Streak Coaster on your right and the Marina on the left) and follow it all around the peninsula to the hotel- follow the signs. WARNING! There is a stop sign or two on this road, where there's a pedestrian crossing between the Marina Gate and - you guessed it- the Marina. If you don't expect it you could get surprised with pedestrians, especially park workers. They NEVER look for cars coming!

When in the hotel, be sure to look for old pictures of the park. They decorate the walls in many of the hallways and are really interesting.

We loved our stay at the renovated Hotel Breakers. It is a high quality resort that is just a hop, skip, and a jump outside of the park. Make sure to take the hotel shuttle to the entrance closest to the marina - it is the least used, but affords the quickest route to Valravn and Millennium Force. Just tell the front desk you need a shuttle to the marina entrance of the park and they'll do the rest. Allow for about ten minutes for the shuttle to arrive and maybe another 5 - 10 for it to get you to the entrance.