I gotta Say I really like the first one.The mood of it just gets me. I like the view of the Biulding in the second one(Clouds in the Windows are nice!).Others are good too.Keep it up man!
1. You cut off your subject, and the bike tire is very distracting. The top right is boring as well, as its blown-out sky.
2. Crooked horizon, and your subject is very small.
3. Blown out sky, underexposed everything else. I actually can't tell which way he is facing, making it confusing.
4. Best of the bunch, but the shadows everywhere make it tough to look at, and your subject is headed out of the frame. Always try to keep him coming into the frame
Keep up the good work though, you don't seem like a total noob. It just takes time