Freshers social events are a bit overrated IMO. What usually happens is a few weeks before the course starts, when people get their info pack about uni, it will include some info from the Students' Union about events being promoted by the SU during the first two weeks. A lot of students will then think oh this is what the social life is going to be like, so I need to get tickets for all these in advance.
Then when you get there, you realise the SU socials are a small part of the town/city activity in the place you have gone to uni, and as you make friends in your halls/flat people will be picking up flyers from different places in town and saying hey lets go here and suddenly you find everyone is going to that and you're trying to get rid of your ticket for the SU school disco or struggling to find someone to go with.
My tip is only get one or two of those tickets at most, maybe none at all. If there's a facebook group where you can find people in your halls/on your course before then post on there about the freshers' events and see if other people are up for going to them - if you can agree something before then go for it, otherwise there's nothing wrong with just turning up with no plans and going with the flow.