I was working on a few sketches for a personal project (and for my portfolio, of course) and started with the main character. I am pretty sure it still has tons of flaws proportion and lighting-wise, still I would love to have some feedback in order to achieve a really good starting point for this guy.
Don't be intimidated, even the best started somewhere and your English is understandable. One tip, thanking in advance seems to annoy some people. Just a heads up.
I see you have some anatomy and consistency problems. You ought to start by picking a viewpoint and lighting scheme and stick with it for the entire piece. The portrait sketch for instance has different parts seen from slightly different angles, with the two eyes as most obvious ones. With the rendering, it's strange to have some parts lit from one side, and then other parts lit from another. They all have to match the same scheme or be lit by explainable variations.
Heya Neon. Not bad!
Looking at these, I suggest doing lots of nose and hands studies (both from real life ref and also how they're handled in graphic art) as I sense an awkwardness/uncertainty especially with noses.