It really depends on what foot traffic the store gets I would personally talk to some of the workers there to see how much business the shoe department gets. If it were me I'd try it for at least a month. Reason being is you could make a lot of money depending on the business.
As far as meeting a quota, it really depends on management. I had management that didn't really care about quota and would work with you. But there's management that would put you on a performance plan.
Plus if you have a return you have to pay it back with commission. So say you have a 300 dollar return in one pay period, you have to pay it back in commission the next week
Those are the risks that you are taking.