No, you do not. You could have it as /cgi-bin/script_name/id -- and then use CGI's path_info method to get the appropriate info. If you're really into it, I would recommend Dancer or Mojolicious over bare-bones CGI. One of the big wins for those two frameworks are the router DSL they provide that abstracts all that low-level path_info/param handling away.

Also, since you're really at the beginning web developer stage, seek out a local Perl Mongers meeting for assistance.