what we learn today are only a slice of the tip of the iceberg. it's a good start for all in their journey to the world of post processing particularly those with S5pro.
there are many more free softwares that work like ps such as gimp and a few more......can't recall right now. you can explore them too at your own time.
Don't worry. This happened to me also when I first learn Photoshop. It was Photoshop version 1.5. The books they had back then were too technical and nothing that a layman can understand. Now, it is a lot better.