I was attending a photography seminar with 2 excellent speakers when one of them asked " What is the difference between a snapshot and a photograph " I didn't have a clue, so I sat up and paid closer attention. She explained that a snapshot is 2 dimensional, height and width, while a photograph is 3 dimensional. It has a depth that a snapshot does not. The light bulb in the little cloud over my head lit up like a lighthouse beacon !! Bells and whistles started going off in my head ! I thought back to some memorable scenes I had photographed that just looked flat, not at all like I would have liked.
She went on to explain that a photograph has a foreground element, a mid range element, and a distant element. A photograph has intentional composition. It has a visual flow from front to back. A google search revealed that elements of composition are: patterns, texture, symmetry, asymmetry, depth of field, lines, curves, frames, contrast, color, viewpoint, depth, negative space, filled space, foreground, background, visual tension, shapes. While only a few of these will come into play in any one particular photograph, you should become familiar with each and learn how to incorporate them into your photos.
One very good resource for learning the above is a book by one of the speakers I mentioned earlier. Brenda Tharp's book " Expressive Nature Photography " is an excellent book to learn about these elements. Along with definitions and explanations, she includes many great photos that demonstrate what she is teaching. This book is available on Amazon, in both Kindle and paperback versions. You will refer back to this book frequently during your photographing experiences.
As an initial first step, while you are learning about leading lines etc., start thinking " Foreground, Middle ground, Background " when you looking at a scene you want to photograph. This will help you in giving your photos depth. And then compare them to photos you have taken in the past. You will be able to notice the difference in short order.