I'm looking to edit a certain portion of a photograph. Say you have a photograph with two people, one of the individuals is too light and you want to darken them up or the clothes that they are wearing. How do I edit just that individual and not the rest of the image? Or say I have a photo of the ocean with someone standing there, how do I brighten up the ocean but not touch the person standing there?
There are several different methods to do what you want to do. I suggest you first learn about selections. When you select an object in a photo, only the portion of the photo that is selected will be affected by whatever edit you want to make, e.g. select a person and make them lighter or darker. Take a look at this HelpX Article for the basics.