Hi,
As others have pointed out societies are a great way to meet people and make new friends, as you'll all be there due to a shared interest anyway which makes initial conversation easy enough. If you're feeling particularly outgoing, you could even just try speaking to people in queues, your university's shared spaces, and so on. Additionally, you can try and make friends within your seminar groups if you're up for getting involved in discussions.
University events are also a good way to meet people, and if you're in an accommodation building check to see if they put on any events, I met several friends at events ran by my accommodation.
Good luck!
Courtney H