what actually should you say when asking for socials of a girl you barely know?

[enriquecuador]

don't mention looks please as people say I am handsome and tall but I act a little autistic sometimes, I need to ask out this girl I have been thinking about for ages with whom I share some eye contact with but I don't think I have spoken to her, she usually takes the train to and from school and I also take it. I wanna ask her out but all the people around me makes it kinda awkwards. What should I genuinely say to her to get her snapchat or number?

 

[deadstock]

Snap?