Crush!!

So I'm a senoir in high school, and I kinda like this guy. We have the same study hall, but sit on opposite sides. He works where I work, but a different department in the store. He acts like he might like me but idk if he does. Im 5'8 and 208lbs. I'm not very attractive and I have a huge nose and the biggest double chin. I'm not saying I have low self esteem, I don't. I'm just describing myself. But he'll come over to my department and offer to take out our trash and make small convo. He's real cute too. I want to ask for his snapchat, how should I go about it?? Or if not his snap, what should I do to tell him I like him?? Thanks!