Hello everyone,
   I'm a firearms instructor in Colorado and need a little help with firearms laws/regulations in California. I have a student whos family lives here in CO but she lives in California and is a first time gun buyer/owner and knows nothing about firearms. She is training with me here in Colorado while visiting her family and getting the basics down and will travel back to California soon. I'm not very familiar with how everything works in CA. Can anyone here fill me in on what she needs to know as far as CA laws and restrictions go? She wants to purchase a pistol here in CO and bring it home and I know that is not possible. Is there a resource that I could send her way to learn about all of this? Also what pistols are legal in CA? Any help to get started with all of this is greatly appreciated!

There's a lot of discussion in the stickied thread at the top.  The Ca DoJ/Attorney General site does a pretty good job of covering things, there's a summary here.  It's not entirely current.

https://oag.ca.gov/sites/all/files/agweb/pdfs/firearms/pdf/cfl2016.pdf

A quick search will turn up the Handgun Safety roster.  A handgun must be on the roster to be available for transfer via FFL (like sales, imports, etc.,) in Ca.  However there are some exceptions.  Non-roster firearms can be transferred by private party transfers.  There are some people, mostly LEOs, who are not restricted by the roster.  Once they legally possess the handgun, it can be transferred.  Several have gone to jail for being in the firearms business without a license by selling too many off roster handguns.  A person moving to California can bring their firearms.  There is a time frame within which they are supposed to report them.  They can import off roster handguns and subsequently transfer them.  There are intra-familial transfers possible.  "The infrequent transfer of firearms between immediate family members is exempt from the law requiring PPTs to be conducted through a licensed firearms dealer . For purposes of this exemption, “immediate family member” means parent and child, and grandparent and grandchild but does not include brothers or sisters."

Note there are legal requirements for PPTs.  Also federal requirements would apply if the transfer is from an out of state relative.

One can not legally import assault weapons and a few other sorts of firearms that might typically be legal elsewhere (definitions available at the stickies above, etc.) nor ammunition feeding devices over 10 rounds.  So, an off roster handgun must also not be an "assault weapon" under Ca definitions.  CCWs are covered under state law but administered at the county level and maybe a few local chiefs of Police (not remotely common).    Some counties, an impossibility, others fairly straight forward.

Thank you very much! I've been very tied up these past few days but will read over this soon! Appreciate all the info!

She would not be able to buy anything (off-roster) in CO.  However, look closely at the intrafamilial Interstate transfer.  Long story short, mother/father in CO can legally gift her any handgun NOT on the roster, the caveat would be it can only have 10rd mags, and no threaded barrel.  Would have to ship to an FFL in CA.  She would have to have her Firearm Safety Certificate, be of age, and pass the NICS at DROS time. 10-day wait after that.

She could buy something ON roster (example, Glock 19 Gen3), but then still have to ship to FFL in CA. IMO, might as well have her try all the options available to her (in a free state)... and then her parents would have to "know" that's the gift she wants for her birthday (for example).   I'm thinking, more options OFF roster, from an ergnomic standpoint.

That's one of the few exemptions that exist to get off roster handguns into CA.  Good luck!