for a 2nd airbrushed piece you are showing you have an understanding of how things should look, which is a great understanding so early in your journey.
suggestion: make use of paper shield to help control overspray (roof of the building) and keep some areas a little sharper (the teeth, areas around his eyes) printer paper, cereal boxes, post it notes can all be used. lay it flat on your artwork if you want a super sharp line, hold it a bit further away if you want a softer edge.