The face has almost no definition to it same for the hair, it just looks like its floating there. The shirt though looks fine just try to make his face more lively with the recesses and extruding areas of the face like your cheek, nose and so forth. It'll also help to position the eyes/mouth right. Also try to get more value in with a defined light source.
Very nice for a first attempt. But I think we can both see there's something wrong with the eyes. Totally salvageable though. I'd start by erasing the one on the right, and just starting over there. My drawing professor, damn him to hell, did manage to impart one important thing to me. If something is wrong, then always erase it. It's not good enough until it's right.