SS means shutter speed. I am not the right person to help you on how to fix this BG in photoshop...I dont do major modifications in post processing. I'll let someone else field that.
I'm wondering what that BG is? Some sort of screen or fencing? It would be doable, but lots of work to "fix" the BG in post...your best bet would be to carefully "Quick Mask" (QM) the subjects and perch, then apply some gaussian blur to the BG. Personally too much work in this case though (in my opinion) - I wouldn't have the patience to do it!
If your exif is correct, you took this image late in the afternoon. Perhaps a morning shoot with the sun on the other side would provide you with better options for the BG?