I have pain on my left shoulder blade and next to my spine. As well as arm pain and slight numbness in my ring and pinky finger. Also have acid reflux?

Could be shoulder v . Could be shoulder or neck problem. Both can present with same symptoms. This can be shoulder issue with some instability causing nerve symptoms into arm with the pain centered in shoulder or a lateral cervical disc herniation creating shoulder pain and nerve symptoms down the arm or a combination of both! a thorough evualuation by exam & appropriate imaging is needed. Reflux could be otc use.
Consider these: The numbness anatomy suggests ulnar distribution or c8-t-1, nerve compression in the neck, but this could also be seen in thoracic outlet syndrome. Have you had some recent trauma? Testing can reveal the diagnosis. Doubt the stomach issues relate to the arm and shoulder problem.