Hi. I think you set up yourself for a difficult journey by jumping straight into colors/rendering. A very experienced artist may get away with it but us mortals should start with basic construction (e.g. Loomis) and values. I would highly suggest looking up fundamentals on human head construction as well as face planes and features (e.g. Loomis, Artwod has a road for it) and try to draw in greyscale - it will help you to get better grasp of values. As far as masculine features go: humans come in all forms and sizes but unless you draw a specific person rule of the thumbs for men is: sharper lines/features (jaw), longer, more hooked or straight nose, less prominent eyelashes and lips. Cheers!