How can I create a plugin where I can seperate diffrent plugins and not write everything in Main.php

Hey, I want to know how to setup a core, i know there is a main file but what do I need to specify in each file for them to all work. The reason I wanna do this is because I want to add a ban system, staff system, crate system etc. but all together in one plugin. The rest of the other aspect plugins will be seperate but I want to a have a special system and dont want to have like 20 files in plugins folder
Thanks

 

TL;DR: How do I separate my code to several files and not write everything into Main.php?

 

Basically a Core from what ive heard

 

I believe this link might help
https://forums.pmmp.io/threads/writing-a-large-plugin-an-mvc-approach.3503/

 

That helped but, I want to know how the actual file setup works. Like I said if theres anything special needed in the Main.php or something to activate the rest of plugins.