You can bring a gun to California as a visitor but must not keep it concealed on your person.
As a non-resident just visiting the state, you do not have to register your gun and your handguns are not restricted to what is on the Safe Handgun Roster.
If you own it (and it is not an "assault weapon") you can bring it.
You can carry a gun in public in California if you have it holstered and have a concealed permit.
You cannot carry a gun in public in California which the exception of residents in smaller counties or if you have a concealed carry license.
California prohibits people from opening carrying any loaded firearm which includes both long guns and handguns in public.
And under California law the sheriff of any county with a population of under 200,000 people or the chief of police of a city within that county can issue licenses to people to carry a loaded, exposed handgun to residents that qualify.
The gun license in California is only valid in the county where it was issued but are identical to California concealed weapons licenses.
The law in California also prohibits people from legally carrying an exposed and even unloaded handgun upon their person outside of a vehicle in a public place.
Generally you may not carry a concealed firearm on your person in public unless you have a valid Carry Concealed Weapon (CCW) license.
You can however bring your gun into California as a visitor but must not keep it concealed on your person.
As a non-resident just visiting the state, you do not have to register your gun and your handguns are not restricted to what is on the Safe Handgun Roster.
If you own it (and it is not an "assault weapon") you can bring it.
Places you cannot carry a gun in California include.
Gun-free zone dictated by California Administrative Code.
School zones.
Government buildings.
The very specific circumstance of picketing or while you're refusing to work in an organized manner.
Carrying a Concealed Weapon – California Law.
Penal Code § 25400 PC makes it a crime to carry a concealed firearm on your person or in a vehicle (unless you have a valid CCW permit).
This offense can be charged as a misdemeanor or a felony and carries up to 3 years in jail.