Take your time and don't ride above your comfort or skill level.
Let people pass if they need to. They'll let you pass if you need to also (hopefully).
IIRC, there is no passing in the ERC... unless someone stalls, falls over, or forgets where they are going.
I belive it is indeed the ERC conducted by Southern Illinois University, Carbondale.Hometown neighbor. PM me, we'll go for a ride.
These classes can be a LOT of fun. I took one last year and it rained all day, it was still fun.+1 Well worth the time and effort. I've taken the "ERC" twice, used to be run by the State of NJ at no cost. It rained all day on my last one. The rain changed direction for the fifty mile ride home; from vertical to horizontal.