Questions on joining the military with a family..?

[Chris]

I'm 21 and I have a complex set of issues..
1. I'm going to be getting married to my girlfriend before I join (if I do), but she has a son from a different father, would he be covered by my benefits?
2. I also have a baby on the way, who would be born before I join. What kinds of benefits would be available to us?
3. I want to be a graphic designer when I get out of the military. Do you have any advice on what field/branch would be right for me?
4. Would they move with me if I'm sent to another base in the country, or out of the country?
5. Is military life similar to civilian? Like, get up in the morning, go to work, etc? How does it play out?
6. I also want to earn a degree. Any info on this?
7. I really don't want to stay in too long. Is there any enlistment bonuses or penalties on a short term contract?