Refer to the open carry pamplets on the CA part to get some understanding of the complex open carry laws. They should explain the gun free zones, transportation, legal unloaded verses loaded carry and the risk involved. Also may want to consider having an attorney regardless if you OC or not, in CA people like to sue each other alot. The CA BOF and the local PD are also not the best people to ask regarding OC.
handguns brought into the state i think have to be regristeredwithin 60 days or face criminal charges. Also no mags over 10 rounds due to the AWB stillin effect. The site below will have the forums to do what is needed for your XD.
Also calguns.net isanother forum you should join, they are very helpful too if you have more questions on CA gun laws or need to debunk CA gun law myths.