1-Paint.net
2-Shading is probably the hardest for beginners
3-start off with either sprites, or heads and bodies
4-not that i have seen but i might be wrong
5-If youre making graphics for graal, they should have a black outline and the light source is in the top left. Be creative, dont be afraid to make mistakes. Try new stuff, have fun while doing it.
6-you really just have to learn how to do it by actually doing it. i could tell you how i shade things but it probably wont be the best way for you to do it.