Both my son and daughter have taken gymnastics at Splitz in Canton near Joy and Lilley Road. But for 2 & 3 year olds, the parents participate too. At 4, they go to class on their own. They do have a variety of class times and a large waiting area.
My daughter takes dance classes at Central City Dance in Canton at Sheldon and Canton Center Roads. They have wide variety of class times, mostly evenings and weekends. It's too late to sign up for the classes that perform in the recital, but they usually have 5 or 6 week classes starting in February. There generally aren't very many times to choose from in the 5 or 6 week sessions, but if they do still have the shorter sessions, there might be a class that fits your schedule. There is a large waiting room at Central City also, but it's generally pretty full.