How to create your own functionality using the aimeos structure

[David]

How to create your own functionality using the aimeos structure. For example, I want to create a reporting system or a simple chat or an email template builder, while I don't want to create new tables, but I want to use aimeos tables to store data related to my functionality.
How can I organize the folder structure, what interfaces need to be implemented for this so that my code is component-based, with its own logic, views, settings, etc.
From the documentation I understand that I need to create an extension, but I can’t figure out what to do next.
The goal is that at any time I could transfer my simple chat to another project with aimeos. If there are any tutorials on how to do this, you can give a link, I'll take a look.
Sorry if something is not clear, translated the text through google translate.

[aimeos]

An overview of the steps is described here: creating managers