Who cares about age! I've hung out with 6 year olds at shows before.
As for planning what to wear, or just announcing what we are wearing.. I find that a little pointless since everyone at the show will most likely be staring at reptiles the whole time, not other people!
The best way I have found is to have a specific time and place to meet up. I think once we did noon in the lobby area and that worked out well. I'll make a little sign or something XD