I think it was about a boy that wound up in a school with other kids that had powers. I think the story was told from his point of view. Each child was different. One could read minds, a girl could heal people, etc. I think they were held captive. I believe to be trained into a weapon they escaped. I believe wound up taking a car and driving up through California towards Oregon looking for a certain place, they wind up fighting the ones who held them captive.
I read it mid to late 90s and some suggest James Patterson's The Lake House but it wasn't about kids who could fly so that isn't it.