Answer:
In my opinion, a hero is someone who selflessly commits acts of kindness towards others, and not for self-profit, or greed.
Dally is a hero. He gives Ponyboy his jacket, which saves him from serious burns during the fire.
Johnny enters the church that is on fire and saves the lives of some children, but he also saves Ponyboy's life.
Ponyboy gets good grades in school, and his teachers recognize his talent in writing. But he isn't only good in academics. He for sure cares for the other members of the Greaser gang, but he also is kind to people who he doesn't even know!