The glitter would be added with a clearcoat.
I'd sand it and then spray the clear on, but if the cars not metallic you're gonna have issues as non metallic paints dont have clear coat on them normally. Also you'd need a paintbooth to do it. I've done cars in a garage.. but... thats really hardcore, the clear coat fumes fill the air so that when you look from the door of a garage you wont see the car
Plus you'd need an spray gun, a compressor, plus the paint stuff.
Also the clear coat is hard to do as it runs real easily. So might be better off paying few bucks to someone who can shoot the car between jobs at a paintshop.
I hope I didnt discourage you.