I'm quite introverted too, and the main thing I'd advise is not to resign yourself to it. You'll be thrown in with a bunch of random people, and it can take a little bit of wading through the crowd before you find 'your people'. Don't beat yourself up if you don't make bezzie mates in the first couple of days.
Especially during freshers, just push yourself out there. Trust me, introvert or extrovert, everyone's bricking it during that first week.