I need help with confidence...

I'm struggling. I posted a thing about my current crush awhile ago and a lot of people told me to go for it, but my issue is how??? I'm not confident when it comes to this. At all. Him and I are just acquaintances, and he's the exchange student of my old science teacher/new neighbor (its weird and uncomfortable to have her as my neighbor, let alone for her exchange student to be my crush). Do you have any tips? I dogsat for them a few days ago and they're probably going to come by soon and he might be there. I'd like some help, and to at least become good friends with him before he leaves.