Is painting common noun or proper noun?

Yes, the noun painter is a common noun, a Word for any painter of any kind.

A proper noun is the name of a specific person, place, thing, or a title; for example:

Curtis Painter, quarterback, New York Giants

Painter, VA 23420

Painter Hill Road, Woodbury, CT or Painter Hollow Road, Fort Ashby, WV

'The Painter of the Wind', TV series (South Korea)

Corel Painter 12, software