[18M] Help me with this girl!!

I have posted this in some other community too, so if someone from that community sees it, then kindly don't judge me, I'm just a dumbo.

I am in first sem and I go to college by public transport. In that same transport, one girl of different college travels too whose college is 2 km away from mine. So it's not like the usual that I am interested in her, but it's kinda opposite. We never talked till now but I have noticed her sometimes staring at me and today she asked for my id which obviously I gave. What do you think is her intention and how should I talk to her, casually, friendly, or like a stranger.

Edit - Just thought that it would be beneficial for me if I tell that... I'm an extreme level introvert 😶. Like I don't even talk with boys irl girl to bahut dur ki baat he. Although I can talk properly in online.