I have tried creating a .pl file and the keyword "package" throws errors. I have tried creating a .pm file, then putting main code (even "print 'Hello World', before the "1;", and this throws different errors.

That makes no sense. If it works in the .pm, it'll work in the .pl. Another error must have been introduced. (It sounds like a runaway quote or a runaway block to me.)

package AverageJoe;

sub get_name { ${shift(@_)} }


package tom;

our @ISA = 'AverageJoe';

sub new {
   my $class = shift;
   my $text = "This is tom";
   return bless(\$text, $class);
}


package dick;

our @ISA = 'AverageJoe';

sub new {
   my $class = shift;
   my $text = "This is dick";
   return bless(\$text, $class);
}


package main; # Not mod_perl safe.

my $tom  = tom->new();
my $dick = dick->new();

{
   print $tom->get_name(), $/;
   print $dick->get_name(), $/;
}
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I had to make changes since 1) you weren't blessing a reference, and 2) you used $class without declaring or initializing it.