I don't know what course you're doing, but lectures have a lot of people in. Over 100 easily. On the first day of freshers you meet your flat mates and if you're lucky one of them (or maybe you) will arrange what you're going to do for the night.
Depending on how it goes you may spend the rest of the week with them. If it doesn't go too well you will either spend the rest of the week in your room or make new friends.
EDIT: If you meant the first day of your actual course, you'll have an introduction to the course and a light lecture.