oh and drawing furrys/sonic/dragonballz are all a big no-no, they're stylistic pitfalls. YOu can't get out once you fall in.
instead start practicing drawing from photo reference then from your head draw a similart image, do this excersize once daily and you'll be one of the best artists in the world in no time
you don't need pointers on your art, you put forth enough effort into your work that you'll grow as an artist at your own pace as fast as if you had a personal teacher.
That's really all there is to it, keep trying your hardest, and someday your hardest will be better than your favorite artists quick sketches, keep trying your hardest after that and someday your best work will be on par with your favorite Artists work in it's own way (by then you've one, because you've caught up woth the guys who've been drawing forever)
There is one pointer I can give, if you ever draw anything that doesn't challenge you, throw it away and find something else that's so hard your not sure you can do it, "a true artist is never satisfied"
If you really are thireen you have the kinda mind that can do something with your passion, so just keep at it, you'll be better than me by the time you're 17