Here are some things you will discuss during your first appointment.
"What brings you in?"
What's been happening recently that brought you to seek out therapy NOW?
History
You'll go over your general history, education, family, supports, friends, previous mental health history, anything that seems relevant. You most likely won't be able to cover everything, and that's ok! That's what your future sessions are for.
"What goals do you have?"
You don't necessarily have to have this fine tuned, but having a general idea of what you want to get out of therapy will help you and your therapist identify how to move forward after the initial session.
Any questions you have for your therapist!
This is something clients often get stuck on, so here are some things you could ask: "Do you have any specializations?" "How long have you been a therapist" "What is your approach to therapy?" "What should I plan to do in between sessions?"
The majority of the first session is information gathering and assessing whether you might be a good fit for each other. You don't need to have any other expectations going in.