Hi Kiya.
A PsyD is a psychologist.... similar to a PhD only a PsyD is a Doctor of Psychology, rather than Philosophy. The difference between the two degrees is that the PsyD focuses on the clinical and counseling training whereas the PhD focuses more on the research.
A therapist is just a general term-- it can apply to anyone that you see for therapy regardless of the degree-- I have seen a therapist with a PhD as well as two therapists with Masters Degrees in Social Work.
Don't be nervous because your new therapist is a psychologist-- this just means that he/she has gone through extra schooling, is able to administer psychological testing.
As far as advice or questions that you should ask-- well that depends what you are going to therapy for. What would you like to know? Just be open and honest.... if you want to know something, ask. You will probably get answered with another question, but you said you've been in therapy before, so you are probably no stranger to that.
Best of luck in your session. I hope that you find a great connection there.