The main thing you have to do is relax.. The more you stress about it, the more mistakes you will make. Most new riders will have stalls at lights and the such.. Yes it’s reasonable to worry about being rear ended by a car when it happens, but don’t worry about holding them up.. If you have your wits about you, you can restart the bike and be off in a few seconds and the cars behind you will survive. I remember one of the first times it happened to me I freaked out and was so flustered I couldn’t get my bike to restart.. I had to push it to the side so traffic could go by while I calmed down and restarted it. In the grand scheme of life, being held up at a light for a few extra seconds is not going to kill anyone.. And despite what most people say, most car drivers are not going to try to run you over.. They’ll stop and wait for you.
Like Capt Crash said.. Try taking it out early mornings on the weekends and try to get out of the city a bit if you can.. I know the SF traffic can suck at times. Good luck and just remember to stay calm..The worst drivers are the unsure drivers..
Dagger