T.F.
I don't know how the job fairs work. I've been a substitute teacher by choice since 2000. I have seen a LOT of subs end up with jobs at the school where we teach the most.
When you sub you see all the aspects of the teams at a particular school and how well everyone works together.
I only sub at 1 elementary school in Plano and I am kept very busy. I turn jobs down because I am not interested in being there daily.
If the job fair does not land you a job, get into a good substitute system. When you sub at a school and like it...make SURE the teachers have your personal number. That way you are called directly. The voice mail system for Plano rarely calls me....the teachers call their favorites before the allow a job to go to the system.
Best wishes.