How to organize directory site structure in php?

Question

PHP

Let me just say that I am a complete beginner. I am learning by making a website for a company where I currently work as a designer. I am responsible for everything on the site. But in my future work I'm going to focus on the layout of sites (at the moment). The site has already been laid out, but now there are problems with the architecture, PHP and database. Now the pages are made like this - index.php, where the site header, left menu, footer and main content are connected.
Here is an example site (sample) www.rzkk.net/?mod=types&id=7 , mine will have similar sections and structure. But I do not know how to do all this from the inside, especially the directory section. There will be no online store.
The proposed structure is as follows:
Home | About company | Catalog | Photo gallery | Contacts | Questions and answers.
Directory structure:
Catalog -> Catalog sections with a list of products -> description of a specific product.
Tell me how to do next. Should catalog pages be stored in a database or just a set of pages or what? Maybe there is an article where it is considered in detail how this is done. Where to look, php frameworks or somewhere else?
update.
1. Still, I did not understand about the directory structure. Namely. Do product pages need to be in MYSQL? Or should it be for each product on its own page? Or else how?
2. I read about MVC. Understood in general terms, but not completely. This article habrahabr.ru/post/150267/#MVC has applications https://github.com/vitalyswipe/tinymvc/zipball/v0.1with a simple version of a business card site. Please tell me, using the example of this application, where and what will be added and changed and stored when adding a section of the catalog and a unit of production.

Answer 1

look at cms. wordpress modx drupal joomla for example. I would choose modx, the easiest way to figure it out is if you understand at least something in php

Answer 2

No need to reinvent the wheel. Use architectural patterns. I recommend Model-View-Controller.
You can simply learn here: habrahabr.ru/post/150267/#MVC .