My upper arm hurts every time I throw. Do I see general orthopedist?

Sports medicine. If the symptoms are such that you want to see a physician, i would recommend a sports medicine doctor. They are initially trained in a variety of residency programs (orthopedics, internal medicine, family medicine) and then do a subspecialty in sports medicine. They would be a good place to start and would be especially trained in understanding why you have pain with throwing.
Depends. If it is short term rest and local therapy (heat, mineral ice etc) may be reasonable. If it lasts more than a few days without any evidence of improvement then seeing an orthopedist would make sense.