Any tips for how to talk to a girl in your class if you think she’s attractive but you suck at talking to anyone?

I (M19) have this class once a week. There’s two girls in the class that I think are attractive, but idk how to talk to them. The class is mostly women besides me and like three other guys. I haven’t talked to either of them and idk anything about them. I think they’re also friends, so even if I wanted to, I’d probably only be able to ask one out. If I ask one, and she rejects, then she’d probably tell her friends. I don’t really know anything about either of them and I have no idea how to start a convo with them. I’ve been ghosted or rejected by almost every girl I’ve liked, so I’m kinda expecting it to go the same way. We’re always busy in class, so it never really seems like i can talk to anyone. Should I try to talk to one of them, if so, how do I start a convo?