Just a tip if you’ve had your eBay account since before you were 18. Never update your date of birth on either your eBay or PayPal account such that you would have been under 18 when you made the account. I made that mistake and they banned that account, I had to make a new one.
Clubs are a good call. Look into societies at your university, find something that you’re interested in or think you could be interested in. Societies are social in a way that seminars and other course activities are not. Don’t worry if you don’t “click” with anyone immediately, keep attending and do your best to engage in conversations.
I also recommend seeking out a university counsellor. Most universities will have them and their advice can be valuable.