Instantiation

I am making a kinda gun like thingy, and a tool thingy, but I would like to know how to instantiate something INTO an object, Ive actualy wanted to know this for a while.

read the instantiation documentation

It’s located here:

I got it to work kinda. but it load the object, but then it exits play mode…

void Update () {
		if (Input.GetKeyDown("q")) {
			GameObject wepon = Instantiate(Gun) as GameObject;
			wepon.transform.parent =  player.transform;

There
It also give off an error,
NullReferenceException: Object reference not set to an instance of an object
wepequipe.Update () (at Assets/wepequipe.cs:14)