Air Force And Med School

Im currently a junior in hs, i graduate in 2021, and i want to join the air force to become an CRNA. I have a few questions:

~Do I need to take certain classes my senior year to be accepted?
~Am i guaranteed my job after training?
~Will I only focus on my job specifically?
~Do I get to choose my College? More and likely an HBCU school?