Your script is not valid perl syntax. I recommend that you take a closer look at some documentation in order to become more familiar with perl syntax and debugging.

• Getting Started with Perl
• Basic debugging checklist

Here is a modified version of your script that will print the first element of @x, which is 'A'. It will also print all the elements of @x (joined by commas).

#!/usr/bin/env perl

use strict;
use warnings;

my @x = ( 'A', 'B', 'C');
my @y = ( 'C', 'D', 'F');

test(\@x,\@y);

sub test{
    my ($x, $y) = @_;
    print "First element of x is: ", $x->[0], "\n";
    print "All elements of x are: ", join(', ', @{$x}), "\n";
}
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