So i'm not sure about some future plans of mine, possibly college and military?

I am currently going to start going to a community college for an AA in Liberal arts and then going to go to training and become a flight attendant. BUT I've been thinking about doing a degree with ultra sound tech stuff instead. I'm not sure if I want to do college for the ultra sound tech and have it just in case the flight attendant thing doesn't work or just go for that. I am also considering going through the air force to do the medical tech stuff... but i don't know enough on hoe that works either? also how does the air force reserve work?