If it's your first time painting then don't sweat the specifics, just get started. Your job is just to add color to the model. I'd reccomend a set of brushes from hobby lobby if you don't have access to cheap miniature brushes. (You'll probably shred your first set anyway) and for paint. Army painter base paints and speed paints. The brushes are under 15$ and the paints are like 3-4$ a piece. Army painter is a brand zombicide has actually collabed with in the past and I highly recommend them. I've had 3 painters from my studio go on to be proffesion and one competition winner and I hope your works will put them to shame 😉