It’s never too late to start. There’s a free online beginner Linux course starting and it’s recommended by Linus Torvalds, the father of Linux. It is done by the cooperation of The Linux Foundation and edX. The first course, Introduction to Linux is available for free since 1st August (it costed $2400 earlier).
The course is available for free (Audit this Course – free), attendance certificate can be obtained (Try for a Certificate – free), but there’s also a chance to get a verified certificate (Earn a Verified Certificate of Achievement – $250).