Do you think, "do a class" is a plausible phrase? For example, let's say a teacher is going to give a class at 2:30, can he/she say, "I will do a class at 2:30"? Or if he/she is giving a class at the moment, can she say to someone, say, on the phone, "I am doing a class"?
I also wonder if a student can also say that he/she is doing a class when he is given the class. What do you think?