I have a lot of stiffness in my legs, especially challenging when getting out of car, chairs, etc. What could cause this?

Arthritis? Stiffness to legs can be due to a problem with the joints (hips, knees, ankles) or the muscles (quadriceps, hamstrings, calves). If it is the joints the most common condition is osteoarthritis from normal age related wear and tear. Any joint pains in the morning could be a different type of arthritis involving inflammation (e.g. Rheumatoid arthritis). See your primary care physician.
STIFFNESS CAN BE A. Symptom of underlying arthritis or a muscular disorder. Please discuss with your doctor asap.