if you feel like quitting don't. wait until the end of the day and think about it. but then another day is done and your are one step closer. stay positive in the mornings because they can be times of low morale. don't hang around those with bad attitudes. stick with the top guys in you barracks.
Sleep with your PT sweatshirt and sweatpants on. It is cold in Great Lakes.
Keep your mouth shut, do what your asked, keep your boots polished and you will be fine.