It is hard for me to shade, I don't know how to make it look like it's realistic, with shade and all that stuff.

For shading: Look up tutorials, and learn from them. Watch other artists. Learn the anatomy of what you are drawing. Once you have done those, develop your own style! It doesn't have to be realistic. If you want it to be realistic, you will have to practice...a lot. When I first started realism, my drawings were horrible. Now they are believable!...from a distance. Anyways, practice makes better. :)
I do not know what you are working with, traditional or digital. If you are drawing traditional, use different pencils, and pressures.

Thanks so much! I do traditional because it's hard for me to do digital XD So I'll ask my parents to buy me other pencils so that I can do some shading, thanks!!