My horn doesn’t work or the volume button on my sterring wheel

Most likely it is a part called a “Clockspring”. It is a flat band of wire wrapped up inside a black housing behind the steering wheel. It allows the wires that connect to the different options on the steering wheel to stay connected as you turn the wheel. The wires wind up into a tighter wrap in one direction of steering wheel turn and unwinds in the opposite direction of steering wheel turn, just like a spring in a clock or wristwatch. It is not a repairable part and has to be replaced as a unit and it is easy to do. It will require a steering wheel puller. If you do not have a red “Air Bag” warning light on the dash while you are driving you can expect that to come on soon as well. Not all the wires inside the clockspring housing are broken yet. If the Air Bag light in the dash does come ON, it does not mean it is going to deploy, it means it most likely Will Not deploy in and accident.