Fell and the force was on my left shoulder, certain movements are excruciating. Any advice?

It is best that you have your shoulder assessed by a sports injury doctor for proper diagnosis and treatment. In the meantime please follow these simple techniques you can do at home to address pain. We call it the RICE technique:

R= Rest

I= Icing. Apply ice packs for 20 minutes to relieve pain

C= Compression. Wrap your shoulder with bandage to control swelling

E= Elevation. Raise you arm to allow for blood and fluid circulation.

As much as possible avoid using the affected side when lifting a load. Do some simple range of motion exercises.