Linux, as a whole, is a lot to learn, but once you understand the basics of it, the operating system as a whole can be a lot easier to understand and better use for your everyday needs. Starting with the basics, you will learn what file systems are in Linux and how you can utilize them properly, how to partition for reasonably safe use, learn about file and directory ownership and permissions – including extended permissions beyond the normal owner:group:other tiers, and much much more.
Later sections will include more advanced topics, but for now, as a new user, or someone that wants to gain more understanding of linux will find knowing the basics a very good start.