Go get some books, focus on either a specific Linux system or a specific BSD system. Once you master one system each system won't be necessarily easy but it will actually make sense, it will be fun to learn, and you will actually learn. For starters? Doesn't really matter, you choose your progress in this world. Everyone that is experienced has started with something "newb" I suppose, but we all had the drive to find things out for ourselves and learn as much as we can. No OS will teach you linux.