I have no idea where to start on this answer.

Ok. let's start with the obvious ones:

1. You need to put use strict; at the top of every single Perl file you work with.
2. You most especially do NOT want to use soft references. ${'flag_' . $x} is a symbolic reference. There are numerous posts on this site as to why not.
3. A hash is built as so:

   my %labels;
   foreach my $lang (@languages) {
       $labels{"flag_$lang->[1]"} = "Something here";
   }
   [download]

4. Invest the US$20 and buy yourself a copy of Learning Perl which will explain all of this for you.