nj I honestly wouldn't suggest adonihs's brush pack because it has a lot of "detailing" brushes that aren't particularly useful unless you really know what you're doing and want to add polish to a piece.
sarenji, I would suggest
this brush pack, since it really has all the tools you need. the third brush in particular is a life saver if you want to add soft shadows without getting a airbrushed look, which is all kinds of ugly.
you totally have the potential to be a wonderful artist. I can't back up everything nj said enough; practice the fundamentals, and everything else will start to come a bit easier. good luck, and try to have some fun with this!