How can I get boys my age to approach me or want to be around me?

(I need genuine advice. Please no weird DMS. Just talk to me like I’m one of your guy friends)

What makes a guy want to approach a girl? I’m 19 and go to a community college and I see tons of attractive boys there but every time I see them I just sigh because I know they probably have girlfriends or they just wouldn’t be interested in me. No I’m not ugly and no, I’m not fat. Sometimes boys will look at me but I’ve had to learn the hard way that just because a guy looks at you doesn’t mean he finds you attractive or has a crush on you. I remember there was one guy at my job who would always make eye contact with me and I would always catch him staring, but it turns out he had a crush on another girl. Part of me thinks I was hallucinating it. The same thing happened with a boy at my high school when I was 15. It was during Covid and I remember when I took my mask down he thought I was ugly as shit and rejected me. Ever since then I’ve been very self-conscious about every single part of myself and have even gotten things done to my face in order to be more conventionally attractive. I feel like I look the part now, so why doesn’t anyone like me?

It feels like everybody at my school is in a relationship. It’s honestly annoying because I feel like the odd one out. I don’t want to eat date and I don’t want to date a 50-year-old man. I don’t really leave the house in general and I’m a bit awkward but I am willing to work on changing the way I act in public ig that if it means I can make a male friend / or boyfriend. What kind of places do you think I should go and what do you think I should do?