I'm retired Navy and work on a Navy base as a civilian. You need to take MSF before you get a DoD decal for your bike. Also, you are required to dress according to DoD instructions, as well as Navy instructions, as well as Local Command instructions. In other words, the Navy instruction states that you must wear "hard sole shoes", but the local instruction (of one of the commands on the base) states, "over the ankle boots". I'm pretty sure that all the services are pretty much the same. Local Commands can make the regs more stringent, but they cannot lessen them. Typically, you must wear a long sleeve brightly colored jacket or shirt during the day, and something similar at night but with reflective material. Must wear helmet, gloves, and long pants, as well, with either safety glasses or full-face shield. I think some helmets that are not full-face are prohibited. This is just coming from my memory, of course you would be responsible to read the instruction(s).
EDIT: Read your post again. When you transfer from post-to-post, the Marines will move you and the bike, too, depending on how much weight you are transferring with. There shouldn't be a problem. As a Marine, you will be required to abide by the Navy instruction and, as I said earlier, local command instructions.
That's great you are joining the Marines. You'll make it through Boot Camp if you have the right attitude. Just remember that it will be over before you know it, and military life is far different in the "real world" than it is in Boot Camp. They will mess with your mind to see if you can handle it, so if you are ready for that and you're in shape, you'll make it! Good luck MARINE!