Shot this in my garage. Single SB700 in a 24" gridded soft box to my left.
Also it was rather wide 24mm because my garage is rather narrow. Hopefully not distorted too much.
Need to work on some poses, styling etc. Basic by keips66, on Flickr
I don't do portraits, but I would crop this to head and shoulders, the 24 makes your hand look very large. If possible you should try and move away from the wall as well.
Your shadow is quite distracting. The light is working well, but maybe dial it back a bit. For men, it is usually better to try for a "low key" lighting scheme.
As to posing, sit up straight, even place your feet on the floor and slide them back, which will lift your shoulders and chest.