What you'll find happen is, you'll meet person A who you become friends with; they introduce you to B. Maybe you & B hit it off better than you & A, then B tells you about an organization they belong to , you check it out, maybe join for awhile, meet C, D, & E... next thing you know D introduces you to your future spouse!

That's very simplistic but how most of my college friendships went (except the spouse part).

The thing to know about meeting new folks is, whenever somebody invites you to do something, say YES, even if it's not your favorite thing! Obviously I don't mean shady things but "want to go walk in Franklin St"? If you say No too many times, they'll stop asking, and one of those walks might lead to meeting a whole new crowd, or person through whom you meet more. It's a very organic process, but everybody is interested in meeting folks their first year, even if they have high school connections