Hi,
Read and understand as much as you can, you probably won't understand EVERYTHING, but do your best, put your questions to the tutors on-line, do the progress tests as you go, get on-line and do questions on the Bristol Question Bank, try not to get too bogged down on each minute detail.
Do lots and lots of questions and you will find that you get comfortable with the subject and the type of questions which will be asked for the exams.
It is very daunting at first, and remains daunting until you pass the 1st module and realise it is possible. Don't give up, you will have hair pulling, teeth gnashing moments, but then, take a wee break and go back to it later.
Best of luck, I am nearly finished and never thought it possible!!!