Overall not a bad start.

sub get_counting_hash { 
    my @wordArray = @_; 
    my %wordHash;    

    ## OK so you have an array. You'll need to loop over it.
    foreach my $word (@wordArray) {
      
      ## Now you need to populate the hash 
      ## You assign a value to a hash like
      ## $wordHash{$key} = $value;
      ## so you'll need to adapt that to your code
    }
    return %wordHash; 
}
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