Having used both Perl and Python, I will suggest learning Perl first. There are fewer places in Perl where you can inadvertently write something other than you intended.

For one quick example, variables in Python spring into existence (in the current lexical scope) when first assigned. In Perl, (under use strict;) variables must be explicitly declared. This combines with Python's indentation-based block structure to create situations where you can produce a new variable instead of assigning the variable you intended. In Perl, block structure is explicit, using { and }, so those beginner mistakes are more easily caught by the compiler. Even with no strict; and using global variables, Perl is less confusing here, because global variables span the entire package, so you at least will not accidentally create new lexicals, as you can in Python.

Overall, Python and Tcl are more easily embedded than Perl, and tend to be used to script larger systems. Embedding the Perl interpreter has historically been somewhat difficult, and Perl tends to be used for freestanding programs as a result. Perl has a significant presence in automating minor system administration tasks, which was one of Perl's original motivations.

Learning Perl is a huge mountain to climb, but once you have reached that peak, other languages are easier to learn.

My other not-so-big-secret is GNU Emacs. It is an extremely powerful programmer's editor once you learn its unusual commands. Emacs' CPerl mode has been a significant assistance for me for many years now.