I recommend you to go to Dongcheng District, Gulou East Street. There is an outdoor studio that teaches sketching. The color and environment are good, and it is quiet. Not the kind of studio where students take the college entrance examination. The students are all young people who are interested in art, and the teaching varies from person to person, which is regarded as an alternative remedial teaching. The teacher will teach according to your needs.

Baidu can find their blog by searching for "wild painting house"