Good timing, I’m painting up my stuff right now.
My advice is to go acrylic and use a primer. Tamiya makes a primer which comes in a spray paint can and it’s good stuff. Wash your pieces first, let them dry really well, prime, paint and clear coat (again, use Tamiya). I suggest getting an airbrush; I use it for my plastic pieces and the 1/285 micro armour I use with A and A. Once you get good with the airbrush, you’ll never look back.
If you get really crazy you can buy some decal paper for the printer from the local hoppy shop (or whereever), search tactical markings online, cut and paste the images to a word file and print yourself some decals. Make sure you clear coat the decal sheet after printing and let it dry real well before you start cutting, dampening and applying your markings. Decals look really good on aircraft and as flags on naval vessels.
Hope this helped.