The change from school to university can be quite a shock as you move from a highly structured and directed environment to one in which you are expected to organise your own studies and rely on your own thinking to succeed.
Here is an excellent two-part video by Dr Owen Clayton on what to expect in your first year at university and how to manage:
Managing your expectations: some differences between further and higher education.
This, and other useful information, can be found at The English Faculty site.