I'm not in the air force but I'm utterly fascinated by fighter planes and use to wanna be a pilot so I know a few things about it.
First off in order to become a fighter pilot you have to have pretty much outstanding grades, perfect vision, plus I think they do a pretty thorough background check. Remember they are trusting you to fly equipment that are worth many millions of dollars so the training and selection is very very tough.
Second you have to become an officer. The United States Air force takes officer candidates and train them at Colorado Springs. Their requirements for admission are:
1. Be a citizen of the United States.
2. Be unmarried with no dependents.
3. Be of good moral character. (hence background check)
4. Be at least 17 but less than 23 years old by July 1 of your first year of entry.
5. Meet high leadership, academic, physical and medical standards.
You would also need a nomination for the academy either from a Senator or a member of the House of representatives just like West Point.
You could also enlist in the air force. But then you most likely wouldn't be able to be a pilot but someone on the ground. Although I think enlisted men can become helicopter pilots if they qualify.