Hi Nathan, welcome to NPN. From reading your story with the image, your enthusiasm for nature photography comes through clearly. I think you will find NPN critique a good place to learn more, both about composition and post-processing. Taking a step up to Lightroom is a good starting point too, you will be very pleased with what it can do.
As Lon mentioned, you did a pretty nice job with the processing of this image, the exposure, contrast and color all look good. I like that you kept the saturation relatively restrained, with bold fall colors like these it’s sometimes easy to fall into the trap of boosting their saturation even more, but you have do a good jog of avoiding that here
In terms of composition, I think you have found a pretty compelling location, and have told a nice story about it. The reverse S-curve of the river pulls the viewers eye to the fog in the distance. Leading lines are nice, but I believe they have to lead to something of interest to be most effective, and the distant fog is interesting enough to be worth being led to. Placing the rock in the lower right corner (LRC in our critique shorthand) creates a strong compositional element that serves as a nice foreground and framing element at the same time.
I believe that thinking hard about frame edges is an important thing for many people who are relatively early in their photographic journey. It’s easy to get excited about the main subject, in this case the fog, the beautiful fall color, and the river, and then not pay as much attention to the edge of the frame. Avoiding distractions along the edges of the frame is often the difference between a good image, and a great one. . @Preston_Birdwell has already pointed out a couple of those here, the branches on the right, and the desire to see more of the tree on the left.
To me the tree on the left is a distraction as presented, not so much the tree itself, but it’s reflection bothers me, the reflection is cut off, and seems to be coming from nowhere. The reflection feels disconnected from the tree, and this problem is exacerbated by the tree being right on the edge of the frame. Bright objects along the edge of the frame can sometimes pull your eye away from the center of the image, and the tree reflection does that when i view this image.
When taking pictures, I try to force my self to slow down, and carefully study the frame edges to avoid distractions while I’m still in the field. Sometimes you can zoom the lens, or move your feet to another vantage point, and change the composition to avoid distractions. And sometimes you only see the distractions after you get home, but all is not lost. Sometimes you can crop or clone the distractions away after the fact. I have reworked your image to give you some ideas in that regard.
Sometimes less is more. I think the squarish crop places more emphasis on the center of the image, while eliminating the reflection of the tree. And the cloning of the right branches helps too.