There's a really cute chick working at a drive thru that I go to frequently. How do I ask her out without bothering her at work? How can I tell if she thinks I'm cute or not?

Idk but I went to Chick Fil A yesterday and the girl in the drive thru who was taking my order said that I could pay up front instead of with her, then when I got there it turns out it was paid for already. I get that sometimes people pay for the people behind them, but also apparently CFA employees can give out one free meal per month or something so idk maybe she thought I was cute but either way I’ll be thinking about it for another week or three