Advice needed for plasterboard walls

Hi There, I need some help, my bedroom plasterboard walls were never sealed before emulsion was put on them followed by paper years later and the more paint over that. We have stripped off the paper and have found the layer of paint underneath is also coming away, we have some minor dings in the wall as well. What I am askin gis can I sand down the wall to get remaining paint off and tpo make it smooth or would it be easier to get a plasterer to skim the wall??