map a website structure

I'd like to code my own website based on an existing opensource CMS (PrestaShop). There is some nice functionalities but also a bunch of code I won't need for my website (a simple B2B catalog with no fancy stuff). The CMS uses PHP (very different from what I learned 15 years ago) and .tpl files. I'm wondering if there is a way to map a website like an .exe in a decompiler such as IDA in order to see relation between files, calls etc? Cheers