That's a simple lexical declaration of variables.

Your level is indeed very beginner so I recommend you start out with a book or tutorial in Perl, before jumping in both feet. "Learning Perl" by Randal Schwarz is an excellent book, but yopu might muddle along with an online tutorial, like the online version of SImon Cozen's "Beginning Perl".

Once you get some familiarity with the language you can use the reference manual, either at your computer console or on the web. The most important parts here are perlfunc, and perlop.