One perhaps unfortunate aspect of Photoshop, at least the version I have, Pat, is that it will keep track of all of the changes you make to a photo up until the time you close that file, and then all of your history is lost.
Having said that, the Battle Island Light photo above is made up of three different photos taken at different times and places, the foreground rocks, Battle Island itself, and the brooding sky.
Two of the most important concepts to work on understanding are 1) how to make "selections" and 2) what a "layer" is. If there is something within a photo that you want to manage separately (lighting, hue, brightness, etc.) or something you want to import into another photo (in this case the foreground rocks and the sky) you need to first "select" it. Layers are like a photo made up of stacked sheets of mylar, each with its own part of the image which can be managed separately. So in this case, the foreground rocks are in the top layer, the island in the middle, and the sky at the bottom. The composite is what you see. Once you get the stack of layers as you'd like them, you can apply filters or effects (like converting to B&W and adding film grain and a frame) to the whole works.
Trying to figure all this out has been at times frustrating but the process of learning is overall fun. I have found in making these "creations" that it is helpful to have some idea of what you'd like to accomplish before you start, otherwise you can spend hours tweaking and retweaking and never really get anywhere. I hope this helps and I'm sure Jim will have a lot to add.
Al