Us marine corps questions.?

I'm 17 and I'm going to enlist in the corps when i turn 18 and i want to become an MP could you tell me about that like their training and everything you can tell me and i cant decide from active or reserves active i like that you live there but don't get to see family and friends as much and get promoted faster and the mos is not guaranteed(at least that's what my recruiter said) reserves i will get the mos guaranteed and see my family and friends but i don't want to get another job and could you tell me about boot camp what is it it what do you do could you give me the most info you can please thanks