Wax finishes would need stripping to giva a key to a primer first.
Lacquered or stained finish needs a rub down thoroughly with some fine-med paper before primer/undercoat.
Use a good quality satin finish top coat .. like Dulux or Crown WB satin.
you need to buy some special paint that you put over the 'knots' that are always in pine wood furniture to seal them.. if you dont then they will bleed through the paint, and you will be able to see them. you can buy it from somewere like b&q
do the normal preparations before, like sanding, then paint as normal