First, I am not a fighter pilot.  I am a Air Force Academy cadet.

To be a USAF pilot, you will need to get your college degree.  You can commission in three ways, do AFROTC in college, go to the academy, or go to OTS after graduating college.  From there, you need to earn a pilot slot.  This is based on your rank within each program (usually GPA, military, and athletic scores).  While in pilot training, you select what type of aircraft to fly based on your performance (i.e. 1st in the class gets to pick first).

To increase your chances, do well in school, stay fit, play sports, and try to get leadership possitions in whatever clubs or activities you are in.