The Perl language, itself, is comparatively small.   The best way I know of to “learn it” is to continue “automating things at work.”   Then, when $work is not giving you particular things to do, just make-up something to do, and do it.   Make something substantial, consisting of multiple modules and OOP, since that will be the most-realistic scenario.

Learning to program a computer is like learning to swim ... books can only take you so far.

But, with Perl, “swimming” (“DWIMming?”) is really only a small part of it, because Perl (more-so than many other languages) comes with a marina full of boats of all shapes and sizes.   Usually, when you start on a project with Perl, you do so by picking-out a handful of well tested “boats” then stitching them together with code of your own devising.   “Learning about Perl” therefore has a lot to do with “learning about CPAN.”

Thanks to virtual-machine technology (e.g. VMWare or VirtualBox), and dirt-cheap real-big external hard drives, the Linux environment is very easy to get to now.   I”d strongly suggest familiarizing yourself with it a-n-d Windows.   Learn about Perl in both environments.

“Learning about Perl” is an abstract target ... you can’t hit that ... make it concrete.   Make it a bunch of little concrete stepping-stones.