It looks Insanely good for a first try!

If I could critique, which may be a bit difficult because the skin isn't very humanoid, the first thing I would say is that the darkest shadows would typically be towards the inside of the skin (where the arms meet the torso, the legs meet each other, etc). The shadow wouldn't usually be on the outer edges of the skin, especially for humanoid skins

I can't tell if u used hueshifting, and if u didn't, I highly recommend u do, or add a little more, as it'll add a lot more life to the skin :D

Overall it's pretty dang good! Gj :>