My DS goes next week and I've given him the advice my parents gave to me about Freshers Week.
Essentially, don't feel pressured to make make friends quickly. You may well spend the rest of Uni trying to untangle yourself from "friendships" made in the first week who turn out to be people you have little in common with.
Realistically you're far more likely to find "your tribe" not amongst your flat mates but people doing the same course as you or via clubs you have an interest in.
As such it's important not to get disheartened. My DS doesn't drink (hates the taste of alcohol) so he's been a bit worried about how this will come across.
I've looked at the Uni website and actually they have a lot of tea total events during freshers so I've pointed him at those.
I've explained to him that the first few weeks can be tough and overwhelming (and we will always be there if he needs us) but he needs to understand it's "process" and the idea that everyone just magically settles in and connects with "proper" friends straight away is pretty much a myth.
It took me half way through my first term to find my "tribe" and the people I then went on to house share with in my 2nd/3rd years (I had a great time btw).
Social media can be a blessing and a curse. Helps you connect with people but I've said you need to realise people post what they want you to see of their lives, not the reality, so don't get drawn in to believing everyone is having a brilliant time because of upbeat SM posts.
I'm glad you had a good day today and sound like a lovely supportive mum.
I might be posting back for tips of my own in a few weeks!