Time management is huge. You'll have practice, workouts, games, and public appearances, sometimes all in one week! Plus, you know, actually going to class!
Also, be smart. In college there is way more access to alcohol and drugs. Now whether you do them is up to you - but don't be stupid. People will recognize you as a cheerleader and a roll model, whether you think they will or not.
Most importantly, have fun! I just finished my first year of college cheer and it was sooooo much fun! There will be stressful points, but just remember how much fun it can be! Have a great season! :)