"I just read Percy Jackson and the Olympians by Rick Riordan..."
If you want an adaptation: watch Percy Jackson and the Olympians: The Lightning Thief (2010), or listen to the cast recording of The Lightning Thief: The Percy Jackson Musical (on Broadway from October 2019 to January 2020, recording from 2017 Off-Broadway production).
If you liked the spin on mythology: watch Thor (2011)--spin on Norse mythology instead!
"As the son of Odin, king of the Norse gods, Thor will soon inherit the throne of Asgard from his aging father. However, on the day that he is to be crowned, Thor reacts with brutality when the gods' enemies, the Frost Giants, enter the palace in violation of their treaty. As punishment, Odin banishes Thor to Earth. While Loki, Thor's brother, plots mischief in Asgard, Thor, now stripped of his powers, faces his greatest threat."
Marvel Cinematic Universe Wiki, https://marvelcinematicuniverse.fandom.com/wiki/Thor_(film)
If you liked the young hero in a world of magic and adventure: watch Steven Universe (TV Series 2013-2019) and Steven Universe Future (TV Series 2019-2020).
"Steven Universe is set in the fictional town of Beach City, Delmarva, where the Crystal Gems live in an ancient beachside temple and protect humanity from monsters and other threats. The Gems are ageless alien warriors who project female humanoid forms from magical gemstones at the core of their being. The Crystal Gems comprise Garnet, Amethyst, Pearl and Steven—a young, half-human, half-Gem boy who inherited his gemstone from his mother, the Crystal Gems' former leader Rose Quartz. As Steven tries to understand his gradually expanding range of powers, he spends his days with his father Greg, his best friend Connie, his magical pet lion, other residents of Beach City, and the Gems. He explores the abilities inherited from his mother, which include fusion—the ability of Gems to merge their bodies and abilities to form new, more powerful personalities." Wikipedia, https://en.wikipedia.org/wiki/Steven_Universe
"Steven Universe Future follows Steven's everyday life trying to help Gems find new purpose; it also depicts the disappointments he faces with his new life, including the realization that there are things he cannot fix, and his own feelings of aimlessness after successfully liberating the Gem empire. He confronts old foes who are looking for revenge, tries to master a new power that he doesn't fully understand, and is challenged to decide what he wants for his own future." Wikipedia, https://en.wikipedia.org/wiki/Steven_Universe_Future
If you liked the elemental powers or the squad of young heroes in action: watch Avatar: The Last Airbender (TV Series 2005-2008) and The Legend of Korra (TV Series 2012-2014).
"A century ago, the young Avatar Aang, afraid of his new responsibilities, fled from his home and was forced into the ocean by a storm and encased himself in suspended animation in an iceberg near the South Pole. Shortly after, Fire Lord Sozin, the then-ruler of the Fire Nation, launched a world war to expand his nation's empire. Knowing that the Avatar must be an Air Nomad, he carried out a genocide against the Air Nomads with the help of a comet enhancing firebenders' power. One hundred years later, Katara and Sokka, teenagers of the Southern Water Tribe, accidentally discover Aang and revive him." Wikipedia, https://en.wikipedia.org/wiki/Avatar:_The_Last_Airbender
"[The Legend of Korra] picks up seventy years after the end of the Avatar: The Last Airbender story arc with brand new characters and settings. The protagonist of the new series, Korra, the Avatar after Aang, is a hot-headed and rebellious young woman from the Southern Water Tribe who is 'ready to take on the world'. The series follows Korra as she faces the difficult challenges, duties, and responsibilities that come with being the Avatar."
Avatar Wiki, https://avatar.fandom.com/wiki/The_Legend_of_Korra