Actually you ain’t half bad. Watch jakes inking video. First pay attention to line weight. There’s loads of different ways of approaching that. Jake favours heavier lines where the shadow is. Some people in manga style have a darker line around the outside of the characters or main features to break things up. After that look at rendering if you want to. You could go strict black and white and really block out where you want the darks to be. I think it’s harder to do that than cross hatching, even though cross hatching is a longer process. With cross hatching you build up the shading.
But whatever, that’s the point of Inktober. It’s the usual story of volume is what is important, just do it. 31 images later you’ll see you’re own improvement.
Last thing that is useful is to look at black and white art you admire and see if you can replicate the style and technique for your own drawing. Kinda fan art, but it’s only the technique yiu are being a fan of. Try it out, and if you like it then keep it and add another bit of technique from somewhere else.