If i have a felony in California,  Can i own a gun in Nevada? Do Calfornia felonies carry over to Nevada and other states?

Gun ownership laws vary by state, as do the laws on pardons for felons and restoration of your Second Amendment right to possess a firearm.  There are lots of websites that can help you figure out what applies to you.

In Nevada they have laws that broadly define the prohibitions on firearms ownership, including felons who have not been pardoned and anyone otherwise "prohibited by federal law", restraining orders, mentally ill, etc.

Unlike what a lot of people might THINK, there is no universal law in the USA prohibiting a convicted felon from possession of a firearm.  The federal government has only the limited powers granted to it by the States and by the People, and gun control has generally fallen under "taxation" or "interstate commerce".  If you're buying a gun locally, without involving a federally licensed firearms dealer, federal laws don't enter into it.  Yes, even in Vermont (which had only one firearms law until recently) it is illegal to give a firearm to a "known felon".  However, ownership and possession are not "the same thing".

Also, for the terminally ignorant: "a felony" is NOT "a FEDERAL offense." Only a crime under federal laws is "a federal offense" and the vast majority of felonies are prosecuted under state laws, not federal laws, where the penalty for a felony can be "more than one year in prison".

A felony is FEDERAL offense.  A felony is a crime in the entire country - every state.

If you have a felony ANYWHERE ON THE PLANET, US Federal law prohibits you from POSSESSING a gun. It is actually legal to own a gun you already owned when convicted, but you can't legally have access to a gun owned by anyone.

The felons can't have guns law is federal, it applies to all states and all felonies, no matter where they occur.

1 - No;

2 - Yes.

Yor criminal record follows you regardless if where in the world you are...........