Hello nic12385 and welcome to wonderful world of neverending learning Perl.

As pointed by a monk wiser than us, you need some basic understanding of control structures.
Even if the book is aged, i ever suggest the cookbook approach: Perl Cookbook

To go deeper and modern get your copy of precious Modern Perl by chromatic.

About web site inspection take a look at other's Perl programs: i wrote one, but i'm still learning:WebTimeLoad 0.23

HtH
L*