I 2nd dws's response - the very 1st thing you need to do is find out where Perl is installed. I have no experience on OS X, but, try

    perl -V
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at a command prompt - that will print out the @INC array, which tells you the directories that Perl will search for modules.

Also, on Linux you can do

    which perl
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at a command prompt. That will display something like this:

    /usr/bin/perl
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and that is what you should include in your #! line at the very top of each perl script. #!/usr/bin/perl -w.

Once you've got that shebang line right, then if you do

   chmod +x my_program

and then

    ./my_program

it should run - hopefully.
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Again, I have no experience with OS X, so I don't know how much similarity it has to Unix/Linux.

HTH.