I was so nervous before my interviews, I prepared more for them than I do for midterms 😳...reading current events in healthcare, practicing with every single interview question posted on SDN.....in the end, all of the interviews I've had ended up being super easy and relaxed. I was mostly just asked to talk about myself and go into depth about some things I wrote on my applications (i.e. why did you join this organization, etc). So the best thing you can do is just to relax, look over your application, and practice going over the most basic questions (Why pharmacy? Why that particular school? What are your strengths?) Looking back, I can safely say that I over-prepared and over-stressed. I wasn't asked one question regarding healthcare, pharm problems, or even anything situational!
So relax and good luck with your interview!