Try to get to know as many people as possible on your course in the first week. The later you leave it to know people, the more difficult it gets, because people usually start forming their own little circles and it'll be hard to get inside afterwards (although it is perfectly possible, but it'll just be a bit more difficult if you're not naturally outgoing/confident). In the first few lectures, just start introducing yourself to the guy/girl next to you or behind you, ask them which halls they live, are they planning on going out, etc. Theres never a more normal situation than this to start chatting to a complete stranger. Trust me, during the first week, people are very chillaxed and friendly, they're all in the same position as you are, eager to make friends.