How do you make friends when you've spent half your life without any?

I've actually achieved some things this year. I signed up for an activity I was terrified of and enrolled in a new course. I feel like I'm starting to live my life again, but at the same time, I'm finding it really hard to connect with other people. Every time I'm surrounded by people my age (21F), I feel like I don't fit in. I don't know what to talk about, what the friendliest way to talk would be, or if I'm just too much of a loser to even be interesting to them. I guess they don't talk about anything too out of the ordinary, but I still don't know how to handle it. I really want to have friends to go out with and do fun things. I didn't used to have this need to go out partying or just do things that aren't just by myself, but lately, I feel like that "youthful spirit" is waking up inside me, and I want to satisfy it.