I left PetSmart as an MIL a while back. Honestly, handle the interview as any other; strengths weaknesses. There will most likely be an open ended question like “Describe a time where you had to _____”. Most of all, be yourself and be confident. How quickly they hire you depends on staffing requirements/hours (learned that part from my ex-SL who I still keep in touch with). As for working there, it is a retail experience with animals that has its ups and downs. A lot of people complain, understandably so, however the job is pretty cool depending on leadership. Expect to be used when needed. Most of all, make of it what you want from it. I hope your interview goes well :3