void Update () {
if (Input.GetKeyDown(“q”)) {
GameObject wepon = Instantiate(Gun) as GameObject;
wepon.transform.parent = player.transform;
wepon.transform.position = new Vector3(0.37F, -0.3F, 0.5F);
this kinda work, but setting the position does not! it doesn error out, instead it just spawns somewhere else…
wepon.transform.position = new Vector3(0.37F, -0.3F, 0.5F) + player.position;
Try this, the position you’re setting is on the Global Coord. and it should be Local.
Oh, right!
wepon.transform.localPosition = new Vector3(0.37F, -0.3F, 0.5F);
Either should work 
Hope it helps!
The first one doesn't make much sense. It doesn't take scaling and rotation of the player into account. The second one is correct ;)
– Bunny83
Where does it position it? Check the values, what are they? Are they different from the ones that you specify?
– instruct9rMy answer is awaiting moderation. Here, try this: wepon.transform.localPosition = new Vector3(0.37F, -0.3F, 0.5F); or wepon.transform.position = new Vector3(0.37F, -0.3F, 0.5F) + player.position;
– dumytruncps: it's a weapon ;)
– Bunny83Either way keep up the excellent quality writing.
– FoolishTroll