Open an editor. On mint you probably have gedit, nano and vi included with the stock distribution. Type in some Perl code. Save it somewhere. Run it by typing "perl my-script-name".

If you are comfortable with Linux, you can add a shebang line to the top of the script, chmod it to executable, put it in a directory known to $PATH, and run it without explicitly invoking the Perl interpreter.

You will absolutely need to read perlintro, possibly followed by a Perl book such as Learning Perl.