The cut-off for the Marine Corps is 35 so I would imagine it is the same for the Navy with that whole Department of the Navy thing. Marine boot camp was the same for everybody, reserve and active duty. Not sure if that is the case for the Navy or not.
You will still have to go to an MOS school when you get out of Boot camp. I took the shortest school that was available right after boot camp was scheduled to end, Administration (pencil pusher, desk jockey, whatever). Boot camp was 12 weeks long and MOS school another 12. I invested 26 weeks total active duty before I reported to my reserver unit.
Once you get to the reserves, you'll have 5 drill "periods" per month, usually starting at 4:00 PM or so on Friday through Sunday afternoon. Each 4 hr block is a period so you need 20 hours per month.
During the summer, you'll be obligated to two weeks straight at the minimum for drill. I opted for some optional duties like driving the caravan up to Wisconsin or wherever we were going for the two weeks. That usually added another week to my tour.
The pay sucks and you won;t get along with everyone but the experience is something else. I look back now and wish I'd gone active duty. Probably would have seen a lot more.
Good luck and go talk to a recruiter but leave with an open ended discussion. You don't want to be sigining anything just yet.
GT