I'm young and im wondering why my knees are squeking an, why my back always hurt is it because, im not active?

Yes could be. It may muscular and thus if you are deconditioned that can play a role in general pain. There are some widespread pain syndromes like fibromyalgia when the pain is myofascial - in the soft tissues. Exercise can help improve the pain by improving muscular conditioning. When you are evaluated these will be some on the things that will be looked at.
Possibly. Getting regular exercise is the best way to keep joints working well and back muscles in shape and pain-free. If swelling is present or back pain shoots down the legs, tests may be helpful.