Cute pictures.
I'd like to see a variety of framing, not just straight on, head in upper 3rd. Nothing wrong with that, I just like variety. What I like with kid shots are more candid and less posed. I find when kids are too posed, they look too grown up and not like the kids they are. So some action shots, some shots of his looking away from the camera and at something else would be interesting.
In the first image, decide if you include the feet or not. Part of his right shoe and leg are showing.
In the second, watch for dirty clothes. You can probably clean that up in post processing. You also slightly cut his fingers on one hand and most of his fingers on the other. Again, either include them entirely or frame differently so they are not included.
Overall, nice shots thought.
EV is your exposure compensation. It stands for Exposure Values. When you meter a shot, you can chose to let the camera meter it (usually in AV, TV or P) and then tell the camera to slight underexpose (EV -1, -2,...) or overexpose (EV +1, +2,...).
Its controlling the exposure while in a semi automatic mode.
If you were shooting manual mode, you would simply set the shutter, aperture and ISO to a spot where the meter would be at the -1 position.