a "dance class" would be a class where u learn how to dance but not necessarily a class where u actually dance. it seems odd but, maybe, it would be a class where you practice some dance movements, but there is no dance indeed.
a "dancing class" would be a type of "dance class" where all the students are free to show their dancing style, as if they where in a presentation or a competition.
did i go too far?
Student or Learner