Wtf is flirting?

So big weekend for me coming up. I just got into this really awesome friend group and we are volunteering together Friday and Saturday. I like this girl, I have no clue how she feels, could be either way tbh. I've stumbled my way in and out of two relationships but only because I had 3rd party confirmation of interest. I'm not socially awkward or anything and pretty funny so I can hold my own in conversation. How do I figure out interest levels without making shit awkward afterwards?