How to respond to this guy?

I was drunk last night and ended up messaging a guy i used to hook up with. We haven’t hooked up in a year, but he did the thing on snap where you type but don’t say anything. I had liquid courage last night and just said hey to him. I haven’t opened it but I know he said “sup.” what do i say now, i’m awful at this stuff 😭😭😭😭😭