Anyone who knows can go to the first-line song and dance troupe to find a teacher to teach alone. The front-line teachers are all skilled artists of the older generation.
If you want to learn to play, you can go to a college art troupe. There are amateur student groups in many places, with perfect systems and cheap fees. Nanjing University of Science and Technology Folk Music Art Troupe is very good, with many piano rooms. Folk music tuition is less than 100 yuan a semester. You can consider hiring a teacher from outside.