Hi and welcome from me too @Felicity73 I really agree with @CheerBear and @Gazza75 's suggestions. Welcome to you too @Gazza75 we haven't met.
I always have high anxiety about a new therapist too. Starting the disclosure process all over again. Making a list over a couple of weeks beforehand works for me - just jotting in point form topics as I think of them e.g. particular experiences, especially traumatic ones, things that have triggered flashbacks, mood swings, memory blocks or surges, what's happening on the harder days. I always say 'the more you tell them, the more specifically they can help you'. And for me it's often been carrying a particular crystal or stone in my pocket that I can feel when I get stumped or emotional during the session. It earths me a bit. Also remembering to focus on breath is really important at times - probably the no. 1 coping strategy. And telling yourself you are in a safe place.
I also agree with starting off by telling them how you feel about being there. They will usually ask questions from there to guide you.
There's also quite a lot of therapists who start the sessions with asking you to do a timeline of your life with them.
If you have a good rapport with the therapist it will get easier to share with them as you build a trusting connection over time.
But also remember - you have the right to shop around if you don't feel a good rapport with them.
And it's ok for you to ask them questions about their education and particular therapy methods they use or areas they are most experienced in.
That's my 2 bobs' worth.