He's a young man, about 13 years old. He started out early with his Earthbending skill and succeeded (and often exceeded) at all endeavors he tried with it. He was often praised so highly by his trainers and other adults that they would say "You might be the next Avatar!" and this tended to inflate his ego to the point that he believed he WOULD be the Avatar! He didn't really consider the other implications that came along with that, though.
When his older brother, a lackluster bender and all around under-achiever, was revealed to be the actual Avatar (through actions on
Zorren's part!), he was devastated and fled his home city. He ended up meeting a group of people, one of whom was ALSO an Avatar, an unheard of situation, he decided to stick it to his brother by supporting this opposition.
He was in a competition & attempting to show off so he chose his older brother, Zenna, as an opponent, knowing that his brother's skills as an Earthbender weren't very good and
Zorren ought to be able to impress the audience even more. During the match, he used TOO much power and Zenna accidentally used AIR Bending ability to defend, thus revealing himself as the Avatar. Everyone was suddenly so interested in the Avatar brother and ignored the prodigy brother (who COULD/SHOULD have been the Avatar!), so he left the city and began travelling, with not much goal in mind.
After leaving the Earth Nation areas, he realized that his usual outfit marked him too clearly as not only a Bender but as a foreigner, too. He slowly found other pieces of clothing from other areas to give himself more of an eclectic clothing style, making it difficult to tell where he was raised. Unintentionally, he has styles from all 4 of the element "nations" and doesn't even really know it.
