Will i be charge for saying "I will kill you if you go near my family"?

You can be charged. Whether you will be is up to the local DA, looking at the facts of the case.

Yes you could be charged, I said that to someone and I got off with the cop giving me a warning I am also a minor, but you could be charged with criminal threatening the cop told me what I did was border line criminal

It is a threat...but depending on the circumstances, the most likely outcome would be a restraining order against you by the people you threaten.

If you feel the need to defend your family (life, health etc), then I would suggest you ask for a restraining order against the people that you feel threatened by.

Not for saying it, but for getting caught saying it. Same with smoking pot. You won't get in trouble smoking pot; every president of modern times has done that. But you get in trouble getting caught smoking pot. So if you want to threaten somebody, make sure they get the message without others being able to testify on it.

Well it is a threat so technically yes, but it is unlikely.

Of course you will. It's called "Felony Menacing and is a crime to threaten to kill someone.