I have a lot of people under 16 contacting me about doing a demo that will get them a deal that will make them rich and famous. If only it was so easy! The real question though is even if that sought after deal came, would it be the right one and the right time?
What I have to say to this is:; what's the rush? Spend your younger years developing as an artist and a writer and figure out exactly what you want to say. The reason most child stars don't have lasting careers is that their inexperience made them make mistakes they otherwise wouldn't have had they been older and more mature.
The way's I encourage young people to develop is by writing songs with different people and try to learn through that experience. Record demos at different studios to get a feel how that process works and more importantly what works for you obtaining the results you want. Most importantly go in with open ears and open to others ideas. There are people with experience that are willing to help and if you listen you'll definitely learn something.
My main point is don't rush into something you're not ready for and remember to take baby steps. It may take a bit longer but your career will be a lot better for it.