Anyone know any good writing sites for young aspiring authors?

[L.J.]

Yes, many many MANY people wish to become one, as do I, and I may be only thirteen but does anyone know any good writing sites? Well, apart from Quizilla and Mibba please? And one more thing, IS it possible for a teenager to become an author? Please help me, I know it's a childish dream but...♥♥ xx