AAU will help of course. The Junior Olympics are highly scouted by both pro and college, it would be good exposure for you. In the world of college sports these days, recruiters are in a very competative market for players, you are at the right age to begin the process. Market yourself to the colleges you like, it works. They cannot really officially talk to you (scholarships, etc.) until the summer before your senior year (which is not far off), but you can get the ball rolling and get yourself on their "watch" list.
As far as your GPA goes, your overall GPA is only a small part of the story. Your "Core" GPA is what your eligibility is based on. Your school counselor can help you with what your "Core" classes are and need to be. It's different with each school, and sometimes for each division you'd like to play at. Requirements for D-I are not he same as D-II, NAIA or D-III.
One word to the wise though. D-I is nice but expand your choices to the other levels too, there are some fantastic colleges in every level, and it's very important for you to find a school that:
1. You're comfortable with if baseball doesn't work out
2. You can afford, scholarships are rarely 100%, most "big" scholarships are books, tuition, and some help towards lodging, the rest is up to you to pay.
3. A team that will give you a chance to compete for a starting job as a freshman, it's no fun to "watch" D-I games when you might be able to "play" in D-II or III.
There's more to come, but as a sophomore, this is about what you need to know for now.
www.leaguelineup.com/sdprospects