The very first thing you need to do as an athlete if you want to play D-1 or D-2 ball is go to www.ncaaclearinghouse.net and sign up. Everyone must do this if they plan on playing college ball in those divisions. The clearinghouse will track your educational progress to make sure you have taken the correct high school core courses.
Wanna know where you stand eligibility wise? Here are the rules regarding course work: GPA and Act Scores.
If you are a junior, you need to take the SAT -> www.collegeboard.com and/or ACT -> www.actstudent.org tests. One of the mistakes athletes make is taking it too late. Plan ahead! The sooner you take one of these tests the easier to get qualified.