lol. I can play that, but Im doing grade 8 now.

You need to have at least some basic experience of the piano (grade 3 standard) to even begin to play that. Dont bother.

Skills like this cannot be learnt very quickly (unless your amazing). I started when I was 6, and Im 15 now. - I dont practice much.

EDIT: You say that you've learnt piano, but how can you not read the notes if you have?
I realise that I have no idea of your keyboarding ability, but really, it is practically impossible for us to help you from here. Perhaps you should pay for some outside of school piano lessons.