Asking a person to pick the next titles for a book club at their first meeting is kind of a big order. Of course, you have no idea what kinds of books the group usually reads. I'd ask for a list of what they've read at least in the last year. That would give some idea of what they seem to prefer. That doesn't mean you have to stick with it, but if they've been reading lighter fare, you may not want to veer suddenly into the dark reaches of the human psyche. I'd want to be sure the group wanted such serious discussions. Not all book groups do. Some just like to get together and chat with the general topic of a book, without many of them actually having read it. It may be that you'll want to find another group for serious discussions. And that's okay, there are lots of book groups out there, f2f and virtual.