Not exactly fantasy, but Great Expectations by Dickens has a boy who grows up totally normal and then has his life transformed by a mysterious benefactor. It doesn't go the way the kid expects.
Also, Sanderson's Stormlight Archive & Tress and the Emerald Sea feature kinds of magic that can be accessible by anyone if they engage with it right. So perhaps give those a go. SA is a long series, but Tress is pretty approachable.