I would advise you to join Mind's page on facebook or have a look at their website if you'd like some clearer information. The advantage of the facebook page is that people receiving similar treatment may be posting and so will be able to advise you clearly, as well as the professionals who frequent the page. Hope this helps to point you in the right direction. Someone close went through CBT so I know where to find the info, but wouldn't want to comment on what to expect :)
I do hope your first session went well for you, and your therapist calmed any nerves you had :)