What happens in the First Week?
Most institutions have a special "induction week" for new students. This is where they do the "official" business of registering the student on their selected course at the university , and also lots of other stuff to introduce university life. There will be lots of "fresher's" events and you will be invited to join lots of societies, which is great fun. As a new student you can expect to have lots of stuff thrown at you during this week and it can be an effort just to keep up with all the material.
It is probably best that you just keep up with what you can, make as many notes as possible and be prepared to revisit the material later. Expect to spent a fair bit of time in queues (although most places will try to keep this to a minimum) and above all don't worry. Everyone you are with is in the same boat, and you will feel very superior to the first years when you are in your second year and they are asking questions like "Where's the Library?"