Look at works of great masters. Anton Corbjin, Henri Cartier-Bresson, Richard Avedon and Bill Brandt are few of the names that pop into my mind.
Then, keep in mind that portraying people and taking photographs are two orthogonal aspects of portrait photography. Practice them separately as well as together.
If to take your first try as an example, it is inferior (=boring) in both ways - it is overexposed, blurry and composition does not have any reasoning behind it. Also, it tells us nothing about the person other than that he has long curly hair, likes to wear black and probably owns a Nikon DSLR.