So about 3-4 weeks I got referred by my GP for therapy (for anxiety)

I got sent a questionnaire in the post to fill out for a telephone appointment which lasts 20 mins.. And today is the day.. I'm feeling rather anxious now, I know that therapy is about changing the way you think and your behaviour.. But other than that I really don't know what to expect..

Has anyone got any experiences they can tell me of?
Or how the first couple of sessions go?
I assume they know most people are nervous and I suppose they try relax you?
Have you had an initial telephone appointment before face to face sessions?

So nervous for the call!!!!