I'd also recommend the fast casual first. Read the guideiines several times so you know what you are looking for. and be sure to note if you need to order a shake or not.
It seems like common sense now, but also be sure to check the restrooms. That was one thing I've forgotten to do on a shop before (not MarketForce), remembered as I was about to pull out of my parking spot, went back in and checked.
With Market Force fast casual, I tend to have to remind myself to look for an outside garbage can.
MF is a good company to start with. You just won't get ratings or much feedback on your shops like some other companies. Just that APPROVED (hopefully) status.