Welcome to POTN!
Here are my comments. Not a professional so take it for what its worth.
Pros: If these are some of your very first shots, they are not too shabby at all. 1,2 & 4 are pretty good. I like the saturation of colors and sharpness. Focus and background blur is good.
Cons: 1&2 look cold. They have a blue cast and 4 has an orangeish cast. This is due to lack of a suitable/customized WB setting. The exposure on 3 is good, but you lost focus on his face and it seems to have landed on his hands or somewhere below. Or, your shutter speed is too slow which causes the moving hands to blur and any motion to cause blurring. The background on 1 &2 is blownout where the sun is lighting up the grass.
The B&W conversions seem to have lost some IQ. Maybe its just me, but they seem a tad softer.
Keep practicing, especially with varied light conditions. That will help you understand a lot of the naunces of exposure and WB.