How To Achieve Perfect Skin in Photoshop With Easy Retouching

i learned frequency separation through you, thankyou, I had a question though, are the settings constant in all photos someone edits?
and i was requesting for a video on how to change a photo background to another one and make it look natural please
im sorry, its alot

Can you do this in Photoshop cc 2015? Which version of Photoshop do you use for retouching, bro , I'm struggling even to get it better.