Fransisco,

In addition to the many pieces of good advice on this post, let me tell you what I think is your greatest asset right now. Your post said: "I am a freshman in high school." This means that you have options. I joined the Marines out of college and had only one real option (OCS). You've got the Service Academies, ROTC, and OCS available...and that is a good thing.  Do yourself a favor and gather as much info as you possibly can before making a decision.