Help with United States Naval Academy?

I am a freshman in high school and I have wanted to join the military since i was 9. Over the years i got more serious about it and i know that i want to join the Marine Corps and then after a few years experience go into the special forces. All of this pretty much relies on me getting into the Naval Academy. I know getting into the Academy is like breaking into Fort Knox. I get straight A's and play lacrosse and hockey, small sports down here. There is no way to try to get me off the road i'm on, i know that my future lies in the military. What i need is advice about what i should do throughout High School such as clubs, sports and working out. I would greatly appreciate it if a Military academy alumni, preferably one from USNA, could give me tips and a good idea of what to expect. I've watched the military channel and just about every other military show while other kids watched spongebob. I know alot about the military such as history, weapons, vehicles and tactics. I greatly appreciate all help and advice. Sorry for making you read so much, and if you need anything answered contact me at adam_1927@hotmail.com