Complex sentence: When Eggers was still a child, the family moved to the upscale suburb of Lake Forest, near Chicago, where he attended high school and was a classmate of actor Vince Vaughn.
Split into simpler sentences: When Eggers was still a child, the family moved to the upscale suburb of Lake Forest, near Chicago. He attended high school there and was a classmate of the actor Vince Vaughn.