[Total Light Storm]

I haven't really gotten much help yet. But I can tell you that after reading this thread, I feel less scared and nervous about going to see a therapist. I just have a couple of questions:
-Do parents have to go in during the first session?
-How do I explain my reasons for being in therapy when I don't really even know where to begin?
-What happens if I go the first time, and let's say a couple of times after and I don't let's say feel like I get along with the therapist or I feel kind of akward putting my trust in that person? Can I get a new therapist or will I have to keep the same person?
-How do they determine how long and often sessions should be? Some people have one hour sessions while others have other times and some people have them once a week, twice a week or every other week.
I'm just curious, is it wrong of me to have so many questions?

Sorry if this is sort of the wrong thread for this.