For example, suppose you take pictures mostly while you're on vacation, and you love nature, landscapes, and wildlife. When you're enjoying a great sunset in person, you realize that the photos you took just don't seem to do the view justice. A photography course can critique these pictures and tell you ways to improve. In most landscape pictures, many amateurs forget to apply the Rule of Thirds, that is, to have three distinct parts to their picture. If you just take a picture of the setting sun, your photo might be just too much red or orange. There is nothing that stands out, and your picture looks like the front of a jigsaw puzzle box. However, by applying the Rule of Thirds, you'll know to adjust your angle so that you get some of the land, the sunset, and some untouched sky in the photo as well - three distinct elements help to offset each one so that they stand out more. A basic photography course will of course show you examples of what this means and point out how to apply this simply technique to your own photos.
Another basic lesson taught in a photography course is how to break up your color and add more contrast. Using that same example of a sunset, if you just have reds and oranges in your photo, you won't notice anything in particular. There are just too many bright colors all in one spot. If you adjust your angle or even wait until the sun has set a bit more so that there is less color in the sky, that contrast of the colors will make them that much more outstanding. Your photography course will again have good and bad examples of what this means. Think of it as trying to put together an outfit. If you have too many elements of one design such as stripes or a pattern, the outfit is too busy. But by having one outstanding piece such as a patterned shirt worn against plain pants and under a plain jacket, then you don't seem overwhelmed and the outfit seems less busy.
These are just some basic techniques that anyone can learn in a good standard photography course. It's always best to see these examples in person, as it's sometimes hard to understand what's being meant just with the printed word. Make sure you see examples of the lesson plans for any photography course you're considering signing up for, and ask for examples of the work of the instructor so that you know you're going to get your money's worth for the class.