Love the Archie's Jalopy and the figures really add to its presentation. I still have hunks of the Archie's Jalopy kit that was produced so many years ago. Wish I hadn't broken it up as a kid to glue parts of it to parts of the the Beverley Hillbillies truck.
For figures this small I use a very fine brush or a sharpened toothpick to put the paint on. I use craft acyrlic paints. The most important part is to get the pupils aligned so they aren't looking in different directions. Keep trying, practice helps improve your technique and using water based paints it's easier to clean off if you make a mistake.