My question involves traffic court in the State of: California.

I lost a TBD regarding a speeding ticket in Los Angeles and, at the time, felt it would be the right move to request a trial di novo. As the date approaches, I'm feeling less confident in my defense and would rather take opt for traffic school. I'm guessing this is a big no, but is there any way to speak to someone about changing my plea to no contest and taking traffic school? It was offered with my TBD decision, and I now know full well I should have opted for it then - but hindsight's 20/20. :/

If it's not possible to get out of, two follow-up questions:
a) Can I appear in court and simply request traffic school right off the bat?
b) When I was given my ticket, there was one officer who LIDAR'd me, and another who actually wrote the ticket. Am I correct in thinking that both must appear and testify in order to successfully prove my guilt? If they are not both present, can I make a motion to have the case dismissed?

Sorry if any of these questions are incorrectly worded, or are rudimentary. This is definitely not my area of expertise. Thanks a ton for any words of wisdom you can provide!