Jessica,
I am currently in the USAF and think I might be able to give you a few tips. First and foremost..do good in high school!! Do your best to become or maintain an "A" average, and get involved with student activities. You may ask how this will help you to become a fighter pilot...and I'll tell you. The "easiest" way to become a USAF pilot is to go to the Air Force Academy. This is where High School comes into play. The whole person concept is taken into consideration when applying to the Academy. An endorsement on a formal letter from a Senator or Congressman doesn't hurt matters much either when applying .
Everyone that goes to the Academy has the opportunity to learn to fly (small planes and gliders), and those that excel in the flight program, as well as academics, are usually the first picked to continue on to formal flight training in the Air Force (after you complete school of course). During flight school, depending on how you are doing and your preference, to some extent, they determine what type of aircraft you will be flying. It could be a "heavy", such as a tanker, transport etc., a bomber such as the B-52, B-1, B-2 etc., or a fighter like the F-16 or F-15.
Hope this helps in your quest to be a pilot. If you don't get into the academy, it doesn't mean you can't be a pilot. You do, however, need a four year college degree to get your commision before you do anything. The degree is the one definite variable that is unavoidable.
Bottom line, do good now, try to get into the Academy, if that doesn't work out for you go to college through some ROTC program, join the AF and try that route.
Good luck..KB