(note: SWTFA characters are aged down, yet with same character traits as they were in SWTFA. Kylo Ren is 16, Rey is 13 almost 14, Hux is 15 )
Kylo Ren (Ben Solo): Son of Han Solo. He, like the rest of the cast of Force Awakens, came to Auradon/IoTL as transfer students. Due to his heritage as child of Han Solo and Leia Organa, he was allowed to live in Auradon and go to its prep school as Prince of Alderaan. He eventually gets sent to the Isle due to his Darth Vader-esque personality.
He is shown wearing his normal movie clothes, though during his time at the other Ben's coronation, he wears a military uniform jacket similar to what a First Order officer would wear. Ren also carries his crossguard lightsaber like he did in Star Wars, and is adept with the Force.
His roommate in Auradon Prep is Hux.
Rey: Her parents are unknown. She was sent to live in Auradon, and like Kylo Ren, she was sent to the Isle because of her unknown parents. Some speculate that she is a daughter of a Disney Villain or a Star Wars Villain, though Rey doubts it. She seemed to kind and outgoing. Although she was not royalty, Rey was allowed to go to Auradon Prep under the child of Luke Skywalker. It turns out that she wasn't related to Luke or anyone in the Resistance, she had a royal heritage of her own.
Rey wears her normal Jakku scavenger outfit, but was seen wearing a gown only once. She prefers more practical outfits that she can move and fight in. Rey possesses a quarterstaff like she did in Star Wars. She is also a Force user.
She never chose to have a roommate in AP.
\Brendol Hux II; Son of Brendol Hux I. He lives in the Isle of the Lost, well, his dad did work for the Empire, and little Hux was already is planning to force Auradon into another regime. Hux wasn't allowed to enter AP, but though clever deceit, he went under the guise of the son of Obi Wan to get in. Hux, on the outside, is smart and ruthless, a military tactician at age 15. He doesn't seem really to care about anyone, even the ones he knows well, in fact, he may be more complex than his roommate Kylo Ren.
Hux is prefers to wear uniforms, as symbol of authority and status, though in one scene he wore Jedi robes as his Auradon Prep trick. Although he is not Force sensitive, he is smart and carries a blaster gun like he did in Star Wars.
The Story (in summary) : New descendants were brought to Auradon from the galaxy far, far away. They were sent as transfer students, as a result from constant war in their world. The four villain kids weren't prepared enough to face the skill and technology the new kids showed, in fact, the whole country wasn't prepared. The First Order was being born, and their goal was to annihilate Auradon through a witty scam. The scam was to send kids from the Far Away Galaxy as spies, though this one girl with unknown heritage was to stop this madness and restore balance to the Force…..