Not a bad go - with ambient light.
A nice candid.
It seems you shot it with a very large aperture to ensure a sharp capture, but as a result the DoF is quite thin. His hair and eyes are just in focus with the remainder being blurred. Hard to know without a larger image, but if his face was more in line with the plane of the sensor, then the whole face would have been more in focus, producing a more flattering result.
His pose is OK - his closed-in lips isn't the best look, though.
With kids, I'd always fire off several because you never know when that perfect pose will be made.
If you have it in RAW, you can salvage some of the blown highlights on his L cheek by toning down the temperature and perhaps a touch of Recovery.