Your best friend is waiting for you. Find him/her. It may not happen overnight, but you will find each other.
It is OK to be intimidated by your courses. Some classes will be tough. You may have a professor whose English you can barely understand. You may realize that you will never grasp Physics. Talk to the kids around you. Someone has the same questions that you do, and someone also "gets it". You will find that some classes are easier than your high school classes. Don't skip these classes, you'll want that easy A to boost your GPA.
You will fall asleep in public. It might be in the middle of class, it might be between classes every Monday morning in the library.
On the subject of napping, you will learn to power nap like a champ. You will have 45 minutes between classes. You walk 10 minutes back to your dorm. It takes you 10 minutes to fall asleep. You sleep for 10 minutes, get up, and walk across campus to your next class.
Get your roommates to agree on a code word or phrase to alert you when a roommate has "company". Do college kids still hang dry erase boards on their doors? Never mind, this is probably obsolete, just text each other.
If you need to go home for the weekend go home, but don't go home every weekend. You will miss out on so many memory making opportunities.
Go to parties.
Don't go to too many parties and be smart about where you are going, what you do there and who you go there with.
Respect yourself. Respect the women you meet.
Dorm living makes you a tidier person (usually). You have little living space to share. Respect your roommates' space by not being a complete slob. Change your sheets from time to time. Seriously.
You will start the year caring about what you are wearing, but by Fall Break, you will be wearing warm up pants and a sweatshirt every day. You may or may not have taken a shower in the past 48 hours.
In the middle of winter, don't worry about looking like a fool in a giant coat, gloves and hat. You live in Ohio. You have a long way to walk to class. You will be warm and you can laugh at the idiots without a coat.
Dining Hall food really isn't that terrible.
If the dorm fridges are still the same, a pint of ice cream just barely fits in the freezer part.
Savor this time. Soak it up. These are the last few years before you to enter the really "real" world. Make memories. That campus is a clean slate. Be who you want to be. Learn. Join clubs. Play sports. Have a snowball fight in the quad. Take a few random classes just because they sound interesting. Go to class. Skip class. Fail a test and study like crazy for the next one. Make yourself proud. Hang up that first A that you really worked for on your tiny dorm fridge.
Lastly, I am excited for you (and a little nervous for you) but mostly EXCITED. I am so proud of you, so very proud.
I love you!