Combat Medic question :)!!!(or army in general(: )?

Well I'm currently 16 at the moment. I'm in 11th grade current(I'm taking it throughout the summer) and next year I'm going to be a senior. I was wondering if I had my diploma at 17 if I could join the army on active duty.? Of course I have to get through all the training and stuff. I was considering going into the reserves but I don't want to have to wait 6 months after I turn 18 in order to be officially switched to active duty. Also, Do you have to be a certain age to work on certain jobs in the army? Such as the one I am suggesting right now-a Combat Medic A.K.A Healthcare Specialist. Also, Whenever I go through the training etc. do I have to go to collage? Or am I fine with everything after I'm done with all the training. Also, if you want, I need some questions to write down for a recruiter. What are some goood questions to ask him? Thanks for taking your time to look at my question. It's greatly appreciated! Have a good day.