You will be surprised by how immature the students are. You have been working in a responsible position for 5 years so don't be surprised by the drunken antics of some of the students.
When you get to uni you need to pay for your course before you can register for the course - go to the finance dept. Once you register for the course you will be given a timetable of what modules will run when - you may need to make some decisions on optional courses. If you are not given the timetable when you register for the course then you will get it during the induction in week 0.
You will need a laptop for notetaking - most lecturers post their PowerPoint slides a day or two before the lecture so you can download the slides and then write on them as the lecturer goes through them. If you have taken a social science subject e.g. History/ English/ Law. Then don't be surprised by the amount of free time you have. Typically, in a week you will have 12-15 hours of lectures (large room with lots of students listening to the lecturer) and tutorials (small groups of 15-20 where the lecture material is explored in more informal discussions). For the remaining time, you are meant to self-manage and do the background reading. You will cover 120 units a year - broken down into 10, 15, 20 or 30 credits. For every 10 credits, you are expected to do 100 hours of work - 25 hours of lectures/tutorials and 75 hours of self-managed study.
In week 0 be sure to join at least two societies - you choose which ones you prefer e.g. sports or social club. This will give you a network of people outside of your course.