Selena Gomez, Charlize Theron and more stars hit WE Day California

It was a star-packed day at WE Day California on Thursday at The Forum in Los Angeles.

Charlize Theron, Demi Lovato, Selena Gomez, Seth Rogen and Lauren Miller, Paula Abdul, Big Sean, Martin Sheen, Hannah Simone, Nikki Reed and Ian Somerhalder, Joe Jonas and more big names turned out to support the WE Day initiative, which is a series of global educational events celebrating youth making a difference. The show had nearly 16,000 students in attendance and they were definitely treated to a special day.

Selena Gomez performed her song "Kill Em with Kindness and Demi Lovato sang her breakout hit this year "Stone Cold."

AOL caught up with tons of big names to talk about their own high school experiences and what makes them want to inspire teens to give back.

Check out all the fun photos above -- including a cute photo of Jacob Tremblay and his new puppy -- and listen to some of the fun interviews below.