That's not a bad start, needs some work maybe, but then, don't we all? ;) I know I do! I'm going to attempt to offer some constructive critisism for you...
The hair is pretty good, hair that has spikes is incredibly hard to draw, but it looks ok here, so good work on that! ^^
Proportion. Not too bad! Looks fairly correct. I think the neck might be a tiny bit too wide, and the legs need to be a little longer maybe, but apart form that, that's pretty good too.
Folds. You tried some folds in the t-shirt! That's good :)! Try some in the trousers next time too ^^. There's a nice tutorial here
if you feel like taking a look.
Shoes. The shoes aren't bad (I hate shoes with a vengance), but remember the foot has a shape to it too ;) Your shoes have a slight heel usually, take a look at a pair and see if you need to include it next time ^^.
Also a general, but not necessary tip: When you're done with a drawing, often getting a pen, usually a black one is best, and going over the lines then rubbing out the pencil can make a drawing look a lot neater. Not always the case and it's personal preference really, but just a thought! :)