Yes, it's become a hobby in itself for me. If I like a game and know I'll play it at least somewhat regularly, I'll paint all the miniatures. Usually I'll go for a detailed multicolor paintjob usually.
Don't be scared! It's easier to get decent results than most people think. And you can always paint over the old paint job once you got better. You can even strip paint from minis completely and start over too. So no reason not to start.
You likely want to wash the models in soapwater, let them dry, then prime them before applying the paint. Thin your paints before applying. There are lots of great tutorials on YouTube.
Feel free to ask for feedback or tips on https://lemmy.world/c/tabletopminis. We're pretty chill over there.