Ah, yes, the basics. Forlorn gave some excellent advice there. Before you start going anywhere, having a good destination in mind will be helpful. If you want realism, it's good to start drawing from life. Even if you don't, it's a great way to get the hand-eye coordination and the millions of small, mental things involved with figuring out shapes and folds and how to break down and simplify. Misyne is also pretty spot on. To draw humans, it helps to know what's going on under the skin so you can exaggerate features any way you want to.
I think, in summary, a good step to consider is just learning how to break down complex 3D shapes and draw them, be that from life, other manga/anime you enjoy, photographs, summoning the powers of the universe, or whatever. And of course, have fun with it.