I have no insurance or money to see a doctor, what can I do to treat a possible spinal disc disease/disk stenosis?

Core strengthening. Most treatment plans for back injuries begin with strengthening core (abdominal and lower back) muscle groups and increasing flexibility, particularly in the hamstrings and lower back. Yoga, pilates, and similar programs are very good at accomplishing these goals. Exercise programs based on cycling and swimming are low impact activities, very helpful in rehabilitation and prevention of back pain.
See a social worker. There should be options for you, especially if you are in or near a metro area like naples-tampa. You may qualify for medicaid or a low cost insurance program. Some clinics/hospitals will also take uninsured patients and work with community & state programs for financing.