A year and a half ago I had a three hour job interview with an animal shelter. I was so sure I had the job that I went home and made plans. Lots of plans to help this organization, and the animals in their care.
I never did get the job. So for what it's worth here are a couple non-profit organizations that were part of my plans to help get some of the shelter dogs adopted.
The one closest to you is in California, and is The National Disaster Dog Foundation. I don’t know how far they are from you. They adopt rescue dogs and teach them to become search and rescue dogs. Here is a link to their site. https://searchdogfoundation.org/
The other non-profit organization is Guardian Angel Medical Service Dogs. Their headquarters is located in Williston, Florida. However they serve people in many other states and are growing. I’m not sure if they have offices in California or not but it can't hurt to contact them.
They teach German Shepherds to become Medical Service Dogs. The work that they do is astounding, and life changing for the people they help. Guardian Angel Medical Service Dogs get many of their dogs from animal shelters. Some of their dogs who went on to become Medical Service Dogs were just hours away from being euthanized. Here is a link to their website https://www.medicalservicedogs.org/
I wish you the best with this.