What happens in the first session
What you will be asked, what you do not have to talk about yet, and what the 50 minutes are actually for.
In the first session, Ala mostly listens. You will be asked what brought you, what you have already tried, and what you would want to change, but nothing is required of you that you are not ready to say.
It is normal to arrive without a clear account of the problem. Much of the early work is finding the words, and that is done together rather than expected in advance.
By the end you should have a sense of how the work would go and whether it feels like a fit. If it does not, you will be told so and pointed somewhere more suitable.