Your pain May be from so many causes. I.e. Upper Trapezius Syndrome, Upper Quadrant Syndrome, Postural Deformities (Wrong Postures),
Vitamin D3 or
B12 deficiencies and so on. There are so many causes. So better option is go to any Physiotherapy Clinic and properly examined by a physiotherapist and then learn exercises for ur exact problem. Because there are so many exercises. A physiotherapist can tell best suited exercises for u after detailed examination.