The first script you write: printing Hello World to the screen. Separate statements with semi-colons ;. Separate parameters with comma: ,. Print newlines using \n. 

#!/usr/bin/env perl
use strict;
use warnings;

print "Hello world\n";
print 42, "\n";

chmod u+x hello_world.pl

See also the getting started article and the one about the sh-bang, she-bang or hashbang.