A bit late, but what the hey...
All I can say is if you don't know what to do, just keep your mouth shut and pay attention. In the beginning, they're more than happy to do most of the talking. You'll get a feel for your psych. You'll figure out what they think of you, what they're looking for, what subjects to stay away from, and when you need to lie through your teeth.

Besides, there are tons of psychs out there. If this one goes south, don't be afraid to try someone else. It's your life and your health. No need to waste it on someone who isn't doing the best they can to help you.