Hi SugarPush.👋 I hope you don't mind me sharing a few things here with you.
Maybe you already do this, but when I'm in a new situation with people involved (which is almost never now, but I'm going on my past experiences here), giving a nice smile and a 'hi' can send out your friendly vibe quite well, for starters. You don't have to engage into conversations immediately, but you can slowly build from there perhaps. Or if you happen to notice someone was looking at you, again, a smile, a hi, or both, is sending out a warm vibe. It's good. Or if people in your immediate vicinity are having a friendly convo, and you're standing there listening too in a social kind of way, if they look at you from time to time, it kind of means you're included in the vibe. That's when you can add something to the conversation if you like - so have your opinions and views ready.🙂
Those are my little things I notice regarding casual social type situations. But I do understand the social anxiety element in all this as well, friend. It is a challenge, I know, and oftentimes ones mood plays a role in all this as well. But that's the same with everyone for the most part.
A flower falls, even though we love it; and a weed grows, even though we do not love it. - Dogen