Try to keep as on top of stuff as possible! That sounds pretty obvious, but organisation is the key to success, especially in first year. You'll be overwhelmed by your studies and social stuff and networking and all that jazz, so my advice would be to make sure you have a good study system set up BEFORE you start the semester.
I'm talking a planner, calendar, color-coding your notes, a timetable for your spare time studying, binders for each subject, the works. Otherwise you'll be drowning in notes and textbooks by the third week. I only wish I'd been strictly organised in my first year!