Cannot assign GameObjects when referencing other scripts

What im trying to do is make my texture in this script equal the texture of another script and the same for my gameobject. When I approach the GameObject I wanted to collide with to activate this code this error appeared: NullReference exception object reference not set to an instance of an object. Any help would be great. Thanks.

                 slotPicture =  GetComponent<item>().itemTexture;
                 this.GetComponent<RawImage>().texture = slotPicture;
                 
                 GameObject itemPickedUp = GetComponent<item>().weapon;
                 
                 slot.GetComponent<RawImage>().enabled = true;