Hello emp1953, and welcome to the Monastery!

One of the strengths of Perl is the , which, according to Wikipedia,

is a repository of over 250,000 software modules and accompanying documentation for 39,000 distributions, written in the Perl programming language by over 12,000 contributors.

Clearly, there are too many modules to include them all in a Perl distribution, so users download and install CPAN modules as needed. In this particular case, issuing either

cpan Path::Class
[download]

or

cpanm Path::Class
[download]

from the shell (command line) will install the missing module (assuming you have an internet connection) and allow the script to run correctly. See How do I install a module from CPAN?

Hope that helps,