If you're under 18, consider using writing as a way to express your take on the world.  Write, and find places that will consider your work for publication.  My very first published work when I was 13 was in a magazine called Children's World.

Here's a link to an international K-12 poetry and art contest, River of Words

Skipping Stones is a multicultural magazine that accepts submissions from both adults and children/youth aged 8-16

Young Writer accepts submissions from kids 6-16

When Pakistani girls from an Islamabad school visited India in 2001, 16 year old Alia Amirali wrote this article.  "Peace is possible," Alia said. "People make it possible when they want to. I think 
we want to, so it will happen."

Children's author Aaron Shepard's web site has a special page for Young Authors
 

British writer Jamila Gavin believes everyone ought to have the freedom to write. 

Audrey Couloumbis  and  Miriam Brenaman both read Uma's stories and suggest ways to make them better.  Check out their web sites and their books.  See if you can figure out two things Uma, Audrey, and Miriam have in common.

Meet Uma's friend Roseanne Thong, who lives in Hong Kong (that rhyme crept in there somehow!) and writes picture books for very young readers.