Zone Script is simple java script you need to include into website where you want Lite Ad Server to display creatives (e.g. banners).
So after you have created websites and zones in the Lite Ad Server copy zone script of each zone and paste it into website.
In the case website is yours you need to update it yourself. Its not complex. Just in the place where banner should be displayed paste the script exactly as it is provided by Lite Ad Server.
In the case you are going to display your banners on website you do not have under control (e.g. you have rented ad space on some website) then send zone script to the website owner and instruct him to paste the script in the place where creatives (e.g. banners) should be displayed.