what is the visa application procedure? how to apply? how to pay fee

If you go to PRC for sightseeing purpose, you need to join a tourist group and then ask the travel agency to apply for a group tourist l for you because individual tourist with Pakistan passport is not accepted. You can get the application details from the agency.
Usually, the visa if free of charge for Pakistan passport holders, but the travel agency will charge the fee and different agencies charges different.