So, if you had superpowers, wouldn't your first inclination be to help make the world a better place by fighting crime, raising money for charity, or cleaning up the local government? If you were eighteen?
It would be mine.
Okay, no. It wouldn't. My first inclination would be to get rich and famous. What on earth possessed me to think anyone would do otherwise? I don't know. Early drafts of Novel 2 had impulsively good characters.
"Hey, what shall we do for fun?"
"I know. Let's start a non-profit to clean up and redevelop a blighted neighborhood!"
"No, let's run for city council!"
"Let's risk our lives to save strangers!"
Actually, risking their lives to save strangers is probably the most realistic of the three. People actually do that. People do the others, too, but they have some connection, some motive, something in their lives that leads them to those choices.
Note to Self: Characters should have motives that are easily understood by the reader. They should act in ways that any normal person would act in their situation OR they should have realistic, compelling, and known reasons to act differently.
Alley risks her life to save her brother. Her friends risk theirs because they trust Alley. (And don't give proper weight to the dangers. Nice thing about young adults.) Esha gets paid to work for a non-profit. Peter runs for office because it's a good first step in a political career. Leah's been through hell, and doesn't want to go back. Brian's a teenage boy.
There are--or can be--understandable reasons for anyone to do almost anything. Find them or make them up, but make sure the reader knows them.