After further review after viewing this on a computer screen, your focus seems to be on the man with the hat, most likely due to you playing with the aperture? You really want to broaden your area of focus. If you follow you can see how the guy in the foreground is blurred slightly as he isn't very sharp, while the guy with the hat is the sharpest in the whole photograph as you can see every follicle of his hair.
What settings are you shooting on?
If you really want to learn a lot about shooting you should play with older film cameras! That's what I did, although I'm not the all knowing, I learned all that I know on my own, and thanks to some vintage photography books I found in the attic with my minolta .