You go to the FRS for ~6 months of training (pilots, probably the same for NFOs) in Jacksonville, FL. You select where you are going to end up (Fleet Squadron) while in Advanced based off of NSS. If you do VQ, your training is shorter, but NFOs in VQ go on for more training. Choices:
Kaneohe Bay, HI
Whidbey, WA
Jacksonville, FL
Maine
Rota
Usually the top two picks are Jacksonville and Hawaii, that varies with each class of course.