Ruth,
Don't worry too much about the pre-study stuff. There were people on my course that got theirs at the beginning of the course. I think the material got distributed as a result of feedback from new trainees a couple of years ago saying it would be nice to have an idea of what we'll be learning. It won't make a jot of difference once you start your training. It's the stuff you put on the thumb-drive once you get there that will help.
As others have said, don't stress. Even though I didn't get through the training, it's the best job I've ever had.