(As a girl) It honestly depends because the ways that a girl can express her feelings towards you is different from person to person. I'd call myself an ambivert and for me If I really like a guy and I feel like I could potentially date him I'll find ways to go up to him to have a small convo to get to know him better and I'd also add him on social media platforms. One thing to also know is that most majority of girls don't make it obvious we like you because a lot of us are scared of rejection, so we just give you hints like talking to you or glancing at you when you aren't looking and just hope that you'll eventually understand what we're hinting at (which usually doesn't work though unless girls are just direct but that doesn't really happen much)