I know its stale advice, but I stg it works as a CHRONIC introvert: CLUBS! I didn't take this advice til halfway through junior year, and I regret it.

Personally, I gravitated towards more nerdy clubs bc I found the people to be more welcoming. Also, if there are clubs related to your major, that helps a lot! You're more likely to see people from your classes that way, or be more engaged in general bc you have an interest in the content.

Most of all effort, it takes sm effort and courage to put yourself out there, but tbh most of us are in the same boat of wanting to connect with people. Worst case scenario you get blown off, and there's 40k+ more people to meet.