This could be caused by arthritis or chondromalacia. Many people have cracking in the knees, but this does not necessarily mean they have arthritis. By that I mean, a couple miles or a few miles of walking. Not marathon walking. Walking will lubricate the joints.
Weight is a negative thing for arthritis.
Consider walking in water. This does not have the stresses of walking the normal way, but has all the advantages. When I sleep at night, I get pain in my hips and a stiffness in my lower spine. It depends what you mean by hip. Having some pain in the back is common.