Ooo! Good luck! Just stay calm and be natural. They already read your application, so it'll do you no good to repeat what's on there. You can go more in depth about one you really really care about, but I think they're just looking for someone 3D. Prove to them you're not just book smart. :3
I'm not sure if other schools have this issue as well, but the admin is not exactly the best. Sometimes I wonder if they realize we're humans and need sleep too. :T But some professors are great and you'll find out along the way. The best part is my classmates. They're just amazing. We even formed study groups.
Hope this helps!