To shade like in comics, you need to understand the basics of light sources and the way they create shadows. Also, experiment with different shading styles and tools to find what works best for you. It takes a lot of practice and patience.
Well, start by studying the basic anatomy and proportions. Pay attention to how lines are used to create form and movement. Also, practice a lot to get the hang of it.
You can start by observing how light and shadow interact in real life. Notice where the light comes from and how it creates shadows. Then try to replicate that in your drawings.
At present, there isn't a direct equivalent of Discogs specifically for comics. However, there are several online comic stores and collector communities where you can find and trade comics.
The French have a varied attitude towards comics. Some are passionate about them, while others may not be as interested. It's like any other country - there's a range of opinions and preferences when it comes to comics.