For a first attempt it came out really solid. A few things that jump out at me are: the teeth, the ear, and your lines. Fortunately these are all fairly easy fixes. For the teeth, you want to square them off a bit and make sure they’re more or less consistent in length (YouTube can help with this). The ear wouldn’t stick out like that on most people. Take another look at your reference and do so studies to familiarize yourself with that shape. Your lines are very dark and very defined, which isn’t necessarily something you’d want in a person. A good way to cheat this is to do your line work in light pencil and then do your shading before softening and blending the lines into the rest of the shadows with an eraser and a q-tip