please help me how can i draw my pictures it is hard to draw i try but i cannot i do not know why it is not good!!!what should i do i am new and do not know.
Are you working on paper or digitally?
The answer is really simple: practice, practice, practice, and perhaps enroll in a drawing course. And/or get some good books on drawing (anatomy, shading, etc.).
Carry a blank notebook and pencils with you everywhere, and draw, draw, draw.
If you wish to work digitally, get a Wacom graphics tablet.
Agree with hvanderwegen,
practice drawing, the basics, perspective, shapes, anatomy, just draw and do all toon boom tutorials before you start any project in toon boom 
this is what I am doing right now, learning to draw