My right shoulder is lower than the left shoulder, also my left knee gets painful when I lift gym weights, are they inter-relatrd? Thx a lot doctors.

Probably unrelated. I would think that the shoulder height discrepancy might be related to either a scoliosis or muscular problem affecting the upper back region. The knee pain with exercise is probably related to a specific knee problem and should be evaluated by an orthopedist along with a discussion of the type of exercise which causes problems.
Possibly related. Shoulder height discrepancy and knee pain could be related. This could be due to leg length inequality, scoliosis (curvature of the spine), muscular atrophy, or other issues. See your family doctor to find the cause.