What do I say in an email after an on-campus company networking event?

Hi guys, a BB came to our school and we networked. My main interest is with s&t and I did some networking with associates and such and got 2 emails there. I also talked to the campus recruiter for capital markets and was actually very interested in it and it's now my second choice- I got two emails including the recruiter

How do I email them? It's been one day so I feel like the time is good, resume drop deadline is Saturday so tomorrow/Friday will probably be my absolute latest. Is it too late to even email them? Interviews on campus are in two weeks. Should I thank them? I'm not sure what sorts of questions to ask them, but I don't want to spam their emails with just a thank you without something else that could help my chances with an interview.

Thanks y'all.