I make a list every year of which booths I need to get to, which questions and/or things I'm dropping off or picking up there. Just do a little pre-planning (like your topic here) and have some conversations. There is NOTHING wrong with saying you are new to this and trying to figure out some decisions for later. Also, I always thank them for their time. If you can go 2 days even better. Little pro tip is that most of them are less busy on Sunday than Sat. If you really hit it off, you can offer to help them tear down too and get some interesting conversations that way. Also, for those you are really interested in, get their WhatsApp contact info. That's become the main mode of communication for many of them.