Chuck Harris will probably show up for the ride registration with his mirrors for sale. He hits all the big rides in the area. Get one. Get a few for your friends too, because even though yours will last forever (my Chuck Harris mirror survived a crash I nearly didn't, and I landed right on it), he's getting on in years.
As others have said, be wary of drafting from all angles. Be prepared for fast pacelines passing you too close without warning - if you choose to draft, be very selective about whom you draft and ALWAYS let them know you're there - and keep an eye in your mirror so you'll know if someone's drafting you without asking, and don't be shy about asking them not to if it makes you uncomfortable.
Do get used to signaling to riders and drivers behind you. Not just people who might be drafting, but anyone within eye or earshot. Point with the hand on the same side of you as any hazard before you pass it, and call out what it is (hole, roadkill, bump, gravel...). Stopping, slowing, turning, use the same hand signals you would in a car, but also signal audibly. (Some people say "braking" to mean both "stopping" and "slowing," so be prepared for someone to come to a complete stop in front of you even if they don't actually say "stopping.") "Car back" will get passed up the line, and "car up" gets passed back.
And have fun!
Speed comes from what you put behind you. - Judi Ketteler