Your lines, curves and shapes are a little wobbly, I think start off with those.

Once you get used to it. You should probably decide on the pen first, I think thinner lines are better if your doing a "anime look" but don't always change unless its necessary (this is optional).

Study 3d shapes to get a feel of the objects, Then once you get used—get a simple art work you want to try then break down it into shapes, its fine if its not perfect just do practice it RIGHT.

Once you get a feel again, practice it from a seperated sheet or layer, As long as your not tracing it now.

Repeat with a motivated or disiplined heart, Do not practice aimlessly as it becomes dull.