To become an Air Force pilot, you have to be a commissioned officer, there are few ways you can do that. First you can go through the Air Force Academy, which is probably the most common. Another way is to be in an ROTC program through your college of choice. The last way I know of is to graduate college and join the Air Force through the officer candidate school (OCS).
Regardless of the method you choose, there are certain requirements you must meet:
- Be a U.S. Citizen
- Have any 4 year college degree or be within 365 days of attaining it
- Minimum 2.5 GPA (although I'd be surprised if they took you that low)
- Under the age of 28 by the board convening date
- Have a standing height of 64-77 inches and a sitting height of 34-40 inches
- Have no history of hay fever, asthma, or allergies after the age of 12
- Meet USAF weight and physical conditioning requirements
- Normal color vision
- Meet refraction, accommodation, and astigmatism requirements
- Distance vision cannot exceed 20/20 uncorrected or must be corrected to 20/20 or better
- Near vision cannot exceed 20/40 uncorrected or must be corrected to 20/20 or better
If you've met those requirements you can then go through the Air Force Officer Qualifying Test (AFOQT) and through Military Entrance Processing Station (MEPS) for your intellectual and physical evaluation. If you pass those tests, you may be selected for the Officer Candidate School (if not joining through ROTC or Academy).
After that you go into undergraduate pilot training (UPT) where you spend a year learning to fly through academic and hands-on training. Depending on how you perform at UPT you will receive a seat assignment. Higher scores are selected for fighter training while lower scores move towards transport aircraft. You can voice your opinion on what you want to fly, but ultimately the decision is driven by the needs of the Air Force at the time you graduate UPT.
After UPT, you will move to Advanced Flight Training (AFT) which is between 6 months and a year long depending on the aircraft you've been assigned. After AFT you'll be assigned a squadron and location.
If you don't meet height requirements
There is a waiver process, although getting a waiver for height requirements is extremely rare (if not completely unheard of). The issue is that the ejection systems are designed for a specific height. This process starts by appealing a medical review board which you are allowed to write a letter to argue your position, however even with a waiver you would probably not be assigned a fighter aircraft. You would probably be assigned an aircraft that does not have an ejection system like transport or mid-air refueling aircraft. As RhinoDriver mentions in the comments, the T6 training aircraft is also equipped with an ejection seat and if you can't fly the trainer, you can't progress on.
The only other alternative to be a US Air Force pilot outside of height requirements is to be an unmanned aircraft pilot.
Source 1: U.S. Air Force ROTC Website
Source 2: Department of Defense Article