I'm a beginner too, so I don't know how much help I can be. But seeings how no one else has posted, I'll see what I can do.
The one thing I think would really make these photos work is some fill flash. Even though its bright outside, turn on the flash on your camera, and try taking the shot with it. What it will do is light up the subject's face, and balance out the difference between the sun and the shadow. Right now there's a line from the sun that kind of puts a halo around his head. But with fill flash, this would disappear or be less pronounced.
The look on his face is great, and I like where he is in the shot. I just think a little more lighting on his happy smile would help the photo out. But as a beginner, I could be wrong. Also, if you're happy with the photo, then its great! Anything I feel will pale in comparison to the warm feelings you get looking at this photo. So I may have a tendency to be overcritical since I don't have as much emotionally invested in the photo, you know? Either way, when you're out in the bright sunlight, try popping your flash up, and see if it produces some desirable effects. If it doesn't, then forget what I said.