It would be very difficult to become a nurse after joining the Navy. If you wanted to learn to be a Corpman, the Navy would train you to do this as an Enlisted Corpman. If you want to be a Navy Nurse, you really need to get your BSN in Nursing prior to joining the Navy, but you would be able to join as an Officer instead of Enlisted personnel, which would be better pay. It would be a very difficult journey for you to join the Navy to become a nurse. It is wonderful that you are thinking of serving your country! Best wishes!