Is Creatine good for getting in shape for the Army?

I am 5'10 and a little over 205 lbs and I am enlisting into the United States Army for MP. I will be leaving near the end of this year most likely the fall like august or september. I want to start working out now to get in shape because I am not in the best shape I used to be. I want to have that edge in Boot Camp where I can run and be able to do work out with not as much trouble as I would if I left now. My question basically is Creatine good to workout with to get in shape for the Army, or after im off creatine does all the muscle basically go away and im back at square one? I also have Mass XXX the protein stuff. Or should I basically get rid of the Creatine and just stick with the protein and work out.