click object to open door help

Alright, so im working on a 2d game kind of with some puzzles in it. I want to make a object like a key for example and when you click on it, the item disappears and plays a Quick tone kind of so you know something happens, and a door on the game will open kind of like making the closed door sprite with a collider change sprite to an open door without collider so you can enter. I'm not very experienced so a detailed explanation of what i need to do with the key object, the door and the script would be really appreciated. Thanks.