you'll need paint and clear laquer. sandpaper from 400, 800, 1000, 2000 grit. lastly some car polish (not wax). rubbing compound would be useful here.

first smoothen the surface with 400grit sandpaper. clean it and spray with normal paint colour of your choice. let it dry... gloss or matte makes no difference here. because you need to fill the imperfections first.

then sandpaper with 800 grit sandpaper. then paint. make sure all the paint dusts from the sandpaper is removed before you paint. you can either wash or blow with compressed air.

repeat above until the surface is 100% smooth. 2-3 times should do it. then next coat of paint should be glossy paint. after painting it with glossy paint, then smoothen with 1000grit sandpaper.. you'll notice with glossy paint, the imperfections are more.

paint it again and this time use 2000grit to smoothen the surface. for 1000 and 2000 grit i recommend to wet the surface before sandpaper...

finally apply the final glossy paint. MAKE SURE the room or area you're drying the paint is clear from dusts and insects. after it's fully dry, apply the final clear laquer paint. this time after it dries, polish the surface with car polish or rubbing compound (final detailing).

to preserve the glossy surface, i like to use car wax.