As prior service Air Force, what should I expect at basic training and 12N AIT?

As someone who did the same thing but after 17 years in the AF, you definitely have to put your pride in your back pocket and try to help the people around you. Do not act like a know it all because you have prior service because you will be resented by everyone around you. So, be humble, keep your head low, and take it all in. Oh yeah, practice the ACFT as much as possible. Let me know if you need any more details or advice.

As a Cross Over from another Branch, your treatment in Basic Training, will more than likely be the same as the IET Soldiers. That is, if 12N is OSUT (One Station Unit Training). I know 12B is OSUT, but I am not sure about 12N. IF it is OSUT, you will more than likely be housed in the same barracks as the IET Soldiers. I say this because when I had reclassed to 12B from Medic, I (and the rest of the Reclass Soldiers, to include an E6) were all in the same barracks, just down the hall "away" from the trainees.

Honestly, as to how you are housed and treated will be entirely up to the policy of the training company you get assigned to. There are no guarantees one way or the other for knowing prior to your arrival.

I did not go through Army Basic Training, but I did go through Air Force Basic and Army Officer Candidate school. Make sure you are physically fit (push-ups, sit-ups, running (2-5 miles), ruck marching in full uniform with 30-60lb pack (12-15 miles) (get calluses built up on your feet now), every callisthenic you can think of), able to think while sleep deprived, land navigation with map and compass (day and night), drill and ceremony (Army is different), extreme discipline and respect, and teamwork. If one person is dropped to do pushups, the whole platoon drops with them. If you can do all of this, you will do fine. Do not tell anyone you are prior Air Force. If so, you will be singled out and they will try to wash you out. I know Army Basic is not as tough as OCS/OTS, but that should give you a good idea of what to expect. Be prepared for the worst, and you will survive it. AIT is way more relaxed, but they still expect respect, no sleeping or talking in class, no food, candy, or gum (unless given prior permission). You will still march to places, and 8-9 hour classes and tests. Air Force had nice facilities, equipment, and better food, but the Army is more of a brotherhood with people who have your back. Overall, I liked the Army better out of the two. Good luck. Hang in there and prepare.