>>7636982try the moderndayjames bridgman videos to understand linework, you don't need to study the book, I never did, just watch the videos once or twice
there are some ethan becker videos on using simple shapes for gesture and one specifically for hands, he's annoying but his videos are good
proko videos on gesture with that one dude everyone shits on, all gesture really is is how gravity shifts through the body during an action or standing pose, its mostly defining the shapes of the body in a zigzag pattern, big example of this is the connection of the knee to the shin, you can see it in all sorts of angles since the body has evolved with gravity
hands are hard to learn once you start, inner line work, using gestural shapes and understanding foreshortening should help with getting better with it, also big thing to do is to look at other art that has good hands and rip them off, my method for using reference is to not to copy 1 to 1 but draw a similar pose at a different angle or add some different aspect to it so there's something to learn
all this is just for line work, colouring is a separate branch, I couldn't help much with that