Hey!
I was like you a couple weeks ago when I started with a new T. I was so nervous I almost threw up in his office.
Try and breath. If it helps maybe you can write down what you are seeing T for (if you know). Sometimes I find that helps if I can't talk. Also, they usually take over in the beginning and direct you.
You made the right decision and hopefully you will feel so much better when you get past your first meeting!

T will be welcoming!