Fairly simple, just be transparent and be as flexible as you can. When I applied, I was starting college, and I had no previous job experience. Can't speak for all Publix's, but will train, just don't expect them to hold your hand, and they will let you fend for yourself.

one interview with a store manager and a department manager. More of just a vibes interview especially if your in high school/college. just dress professional and don't be weird. also have an answer for basic questions like "why do you want to work for Publix"

Very easy. Simple questions and basic interview questions. Nothing tricky. Just call back to follow up since the managers seem to forget to call sometimes. There is only one interview process before they call and let you know.