In the state of California how old must a child be in order to determine which schools they attend and if a 14-year-old lives with her mother in Laguna can she go to a Newport school?

You are a minor so it's up to the educational system and your parents to decide where you go to school. Like Canada, in many States you go to the school in your area (perhaps there are 3 schools nearby.) If you want to go to a Newport school then it's strictly up to your parent(s) to decide that. You must have your reasons so sit down with your mother and communicate how you feel. Good luck Marcy Children attend the appropriate school in the district where their parents or legal guardian has established residency. The exceptions to this are court ordered busing or permission from the school superintendent or school board for a non-resident to be admitted to the school of the districts choice, which may or may not be the student's choice.