Hey just felt like i should say something about this topic. A lot of people will ask me how should I learn PHP for pocketmine when all the videos have no voice or don't explain it properly. You can search how to code OOP PHP (Object Oriented PHP) because Procedural PHP wont be much help in pocketmine development. A person I highly recommend watching to get a good understanding of OOP would be Dani Krossing () . Hope this helps ! Best Regards, Ryan
After learning PHP, you can check out this cool website to learn about the Pocketmine API https://pocketmineschool.netlify.app/ Source of website: https://forums.pmmp.io/threads/plugin-tutorial-for-future-developers.25/
I highly recommend using PHPStorm for pocketmine coding because you can add external libraries and it will make your life so easy!