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.
