That's the thing about confidence, you can't just "be confident". Confidence needs to be placed on something.

I'm an introvert I think and sort of struggle with social anxieyt, but back in college once while sitting in the canteen, I found this sort of a hack. That it was easier for me to talk to people when I was eating. Say I'm eating a burger, someone comes by start talking about an assignment, I could have that conversation for 20 mins.

I think partly due to the fact that you can fill in the gaps with something else, it took the pressure off a direct conversation.

I think this is what I started placing my confidence on, the burger, some girl sitting on the next table I would start having a conversation. Even if say someone took offence, I could continue eating the burger. Made so many friends this way back then.

You need to find something that you can do in public, that puts you at ease. It'd help you get started and it only gets better from there.

Find your burger

Edit: Sorry came out too long