The bell doesn’t ring until 8 a.m. at Lincoln High School, but by then freshman Briana Lopez has been awake for hours. The 14-year-old leaves her house in Northern California at 6:30 each morning so she can get to school for a 7 a.m. marching band practice. Worried about the ill effects of sleep deprivation for students, California on Sunday became the first state to mandate a school start time under a new law signed by Gov. Gavin Newsom.