I took one a couple of years ago after I was scammed by the crooked police of Thousand Oaks, CA who gave me a ticket for failing to yield to a "pedestrian" who was in the crosswalk.
Actually, it was a setup and trap....the guy was completely on the other side of the 4 lane + devider street TO Blvd. and I was on the opposite side in the far right lane. This jackazz steps out into traffic and there were no crosswalk lines, he just steps out. I was in the red 911 and couldnt really see until the last minute because there was a big truck to my left and I couldnt possibly see around him and across to the opposite side. Would not have made sense to look over there anyway.... so I got pulled over and the cop was a jerk and gave me this $200 ticket, and then down the block I saw 3 other cops pulled people over for the same thing...the "pedestrian" was actually an undercover cop because he pointed at my car to signal me out to the other cops. Total Scam.....
but I digress...
Regarding traffic school... I took it online but still had to go to a nearby office to drop off the certificated and verify who I was. The office had to be one that was under the jurisdiction of the court that the ticket was issued under. So my advice would be to make sure that you take an online course that has an office near you that is under the jurisdiction of the court that your ticket is under.
You may want to try to fight the ticket trial by declaration first with a letter to the court. I tried that and it didnt work with the crooked Thousand Oaks thing...but it DID work when the crooked cop in Hermosa Beach gave me a ticket for honking my horn at a guy who had cut me off and almost hit me. What an idiot that guy was... so I fought that one by declaration and it was dismissed without penalty!