I use spay cans and have done so for many years. A better approach for a newbie is to buy a small air brush and spray the paint from a spay can into the airbrush jar. This way you can adjust the pressure and put the the paint on lightly. I have a friend who builds contest winning stuff, he uses lacquer over plastic with no primer. Test out the paint on some scrap plastic from the kit you are working on.
Some plastic is more sensitive to paint than others.
Metallic blue 70 GTX, met. The more brittle the plastic the worse the paint will react to it. Try some paint on clear to see what happens. I have a huge collection of model kits but no time, someday I hope to get back at it.