Author and activist Marley Dias, 15, founded the movement #1000BlackGirlBooks in 2015 after her teacher assigned three books to read during the school year -- all featuring white boys and their dogs as main characters.

"I was getting access to a singular experience and that was super frustrating for me as someone who had parents that had always promoted diversity," Dias told "GMA."

That's when she took matters into her own hands. With the help and support of her mother, Dias set out to collect 1,000 books that featured Black girls as the lead character. Through her own work and the power of social media, Dias has now collected 12,000 of these books to donate to schools and communities.

"The goal of the campaign started as a way for me to just collect and donate books, but has now moved into a movement that not only focuses on representation, but focuses on motivating other kids to believe that they can change the world and that their passions and frustrations are just as valid as mine," she said.

As a result of her work, Dias spoke at the White House's United State of Women alongside Michelle Obama and Oprah Winfrey, the Forbes Women's Summit and the Social Innovation Summit. She was an editor-in-residence at Elle magazine, where she interviewed other female change makers such as Ava DuVernay, Misty Copeland and Hillary Clinton. In 2018, she was named one of the 25 most influential teens by Time magazine. That same year, Dias became the youngest member ever to be named to Forbes' 30 Under 30 list -- a title she still holds.

Two years ago, the teen compiled all that she'd learned and published her own book, "Marley Dias Gets It Done: And So Can You!" a guide that explores topics including activism, social justice and using social media for good. She explains to young readers how they can use their strengths and passions to make a positive impact in their own communities.

Now she's sharing her five tips to becoming an effective youth activist with "GMA."

1. Find and use your passions to solve social frustrations

"Some of these frustrations for me were lack of diversity. But for you, it could be homelessness, economic segregation or sexism. So look around you and figure out what things frustrate you. What do you want to do to solve those issues?" she said.

2. Combine your passions with emotion and information

"Your passions and how you feel are super important and that should be valued. But it's also important to know your facts and understand how these issues affect others."

3. Ask for help and use your resources wisely

"Find a caring and informed adult, and share these opinions and ideas. And for parents, listen to your kids and support them, even if their ideas seem wacky or wild or radical at the beginning. Support them, guide them and help them feel as though their ideas matter."

4. Think and act locally

"Get to know the people in your neighborhood. Understand how this issue affects your community, and how it moves beyond your home and beyond the spaces that you might be used to."

5. Be the change you want to see in the world

"If every day you say Black Lives Matter, then you need to believe it and act in it every single way. The experiences of all of us are different, and we need to value and respect other people's opinions, and become informed and help others."

Dias said it's just as important for kids to speak out as it is for parents to listen.

"My biggest takeaway for parents is always listen to your kids and ask them questions," she said. "Remember that they don't have to wait until they grow up to change the world, to be something, to do something."

And for kids, the activist said it's their own unique perspectives that make a campaign special.

"To take that first step of bravery is to really focus on finding your passions and not think that you have to wait to be great," she said. "It doesn't take anything super special or different, or necessarily a lot of money or fame or things like that, to really create something amazing."