I interviewed for the adult Psy.D. program several years ago. Not sure which program you are interviewing for. I think it really will depend on which faculty you interview with, but overall it was very very laid back and casual. It was my first grad school interview and I remember feeling so much relief about how NOT scary it was. It's not a mentor model program, so you will be paired with random faculty but you can still look them up in advance to at least have an idea of their interest so you can show that you did your research. Then just prepare all of the standard interview questions why clinical psychology? why this program? tell us about yourself? etc. and you should be good to go! good luck!