What should I do? (Read desc)

So about 2 months ago I started to think a boy might like me. Due to this I started paying more attention to him and ended up developing a legitimate crush myself. At this point me and all my friends are almost completely sure he likes me. My problem is we aren't friends. We don't talk unless seated together in our constantly changing math seats. So I really don't know how to approach him without it being weird and out of nowhere. Talking to your crush is always awkward but it gets 10x more when your crush is blushing and nervous while you talk. What should I do?