The time it takes to learn Linux can vary, depending on whether you have existing background knowledge of other operating systems and how deep of an understanding you want to gain. For beginners learning Linux to pursue a career in IT or software administration, you may only need a basic understanding of how to navigate and execute functions using Linux and how applications built on Linux behave. If you plan to become an ethical hacker, or pentester, you may need a more in-depth knowledge of Linux security procedures and a skill in manipulating Linux programs. You can learn Linux on your own time by seeking out video tutorials and online courses. There are plenty of courses available on Udemy that teach the fundamentals of Linux and more advanced Linux skills.