There are 10 sections in California, yeah they pick from the section champs and the sections are broken up into North Section and South Section and one from each is selected.
North/South Section Breakdown
The Northern schools will be comprised of member schools of the: Central Coast, North Coast,Northern, Oakland, San Francisco and Sac-Joaquin Sections.
Southern schools will be comprised of member schools of the: Central,
Los Angeles, Southern and San Diego Sections.