the legs look a little short and his waist is quite thin. these may be style choices but i think the legs need a bit more length and the legs/feet could definitely use some more definition. particularly around the ankles and knees.
otherwise a nice clean start. i don't think your shading quite adds up but i'm sure you will receive the help to improve it.
one last note: try removing some of the shadow around the central chest/breast area. looks a little boob like.
