Your priority now is to finish High School Strong. Complete your varsity sports, clubs and most important, your high school classes strong. You should also start working out a few times a week to prepare your self for ROTC. Running, sittups and pushups should be part of your routine. Join a gym if you can and lift. Do not overdo it initially. Slowly work into a good program. PT tests will be very important in college. Start now if you can. The time you put in will pay off next year. Best of luck to you all.