Everything said above is solid advice. I just commissioned out of ROTC, going to upt in January. Never got a scholarship, I came in as a 250. Make friends with everyone, if you stay in the program you are going to be spending a lot of time with these dudes/dude-ets. Be yourself, never try to through anyone under the bus to get ahead, do everything you can to help others. Memorize as much of the knowledge as possible, and show up to your wings extra activities. Kick ass with grades, and get in the gym and get in best shape as you can. Try to latch on to a solid 200 and POC outside of AF time and get as much knowledge from them as you can. I owe my career to a kick ass guy who was a year ahead of me and helped me out whenever I needed. You will learn more about how to make it through the program by hanging out and drinking a beer with some solid 200s and upperclassman than you ever will from reading a manual. Make sure you talk to POC/cadre about the best times to take your afoqt and tbas.
Lastly, make friends with people who are not in ROTC, and do plenty of non ROTC activities. People who make ROTC their entire college life either burn out or become douches who miss out on some of the best years of their life. Drink some beer, meet some ladies, and have fun in school. Good luck
P.S. you probably won't ever march on AD as said above, you might once or twice as upper class man (POC), but with all the budget cuts marching and power points are about the only thing ROTC has money for anymore, so as much as it sucks, get good at it if means that what it takes to get to upt.
Edit for bad grammar. To much beer, not enough English class.