1. RUN RUN RUN RUN, and then run with weights on your ankles (especially if you are from a sea level area). Be in the absolute best physical condition of your life.
2. You may have been the emperor of your highschool, the high priestess of the IB program.... you will NOT be so on I-Day or on any other day until Recognition (March). Check your attitude at the door and learn some team work skills. Learn to take orders and learn to bring your other squad mates along.
3. Quit whining about everything that is uncomfortable, inconvenient, not as you'd like it. Adult life can be like that, a lot.
4. Remember, and try to remind Mom and Dad as gently as possible, you are not in civilian college, but are now a member of the US Military. You have full adult rights (except drinking, and no pot for you, despite Colorado's idiocy), but also, full adult responsibilities. Is it fair? Maybe, maybe not. Know it going in and you won't be so snarky when you're there.
5. Your high school, despite what all your neighbors have told you, is not the end all/be all of the teen universe. State champs in Lacrosse? Yay! Best Math program in the county? Boy howdy! You are just as likely to room with a kid who's never seen a cow in real life, never ridden a commuter train, never mucked out a horse stall, never seen the ocean, never driven a car, never had a sibling, never had a room he didn't share with his ten brothers. In other words, you are in a new, and very real, world now, and learn to accept people as individuals instead of as part of pre-defined groups. (Though NARPs do come to mind, and they are a majority, not a minority at USAFA {NARP: Non-Athletic Regular Person}
6. Recall that your parents still think of you, especially your dear and devoted mother who gave you life, kissed your booboos, cheered on your 5th grade high jump, and sat in the rain while you ran around a soccer field for 3 hours, your parents will always first think of you as Baby Johnny, or Lil Susie. Don't get your flight suit all in a twist because they call you "too often" or send you your favorite Rice Krispie treats in the mail. Set up a weekly time (after BCT) to chat, and don't forget them at home. They walk past your empty bed every day (and want to make it into Mom's Sewing Extravaganza or Dad's Tool Time TruckStop), wondering how things are for you.
Be good and go to Church.