How to make the function of adding a category and a product?

Question

CMS

How to make the function of adding categories and products?
I already pulled the layout on modx.
That is, there are categories in a tiled form, when you click it, you go to a new page with a new template, this template has a left side menu with categories, and on the right side there are product thumbnails, each thumbnail has a more detailed button, when you click on it, it flips on the Description and Characteristics of the goods.
Structure: Categories -> Products -> Product (Description and Feature).
For convenience, I drew an illustration in paint.

PS remotely familiar with miniShop