I am experiencing some tightness and tingling in the sides and back of my head. I also have some stiffness on the left side of my neck.?

Osteoarthritis. At your age degenerative disease of spine is most common cause of your symptoms. Tingling in head is from irritation or pinching of nerve in upper part of neck.
Muscle tension. Muscle tension headaches often present as head pain or tightness and neck tightness. However, tingling can also be from early shingles symptoms. The neck symptoms could also be due to swollen lymph nodes. See your doctor so he or she can examine you and narrow the diagnosis.