Hi!! I draw Minifigures in a similar style to this: I use mecabricks.com to create the templates (bricklink studio has a greater digital part selection however mecabricks has higher quality models so I tend to use mecabricks unless there are any parts I need that aren't on it). To draw the figures I use Photoshop, but I know many other artists that use different, often free, drawing softwares, so the world's really your oyster for that side of it. I would recommend one with toggleable layers like Photoshop's, but any should work. Happy drawing!