beginner question on wordpress plugins?

Hey everyone new to the coding world.

Ive been going through some of the fundamentals courses right now im on php. Im getting the grasp of everything pretty easily.

I would like to learn how to develop some of these big plugins that i see on wordpress. Like these popup boxes or chat boxes that come with these cool drag and drop editors within the admin panel of wordpress.

Im just seeing if i could get tips on exactly what courses and what not to learn to develop such plugins. One plugin i like is by thrive it has optin boxes, widgets, overlays, etc.

Im also seeing if you guys could shed some knowledge for me, on exactly how are the plugin features like the drag and drop editor features in the admin side in wordpress created?

I realize theres probably a ton of ways to get one thing done but im just seeing how the process goes from concept - to blueprint/layout- to execution.

Thanks guys, All the best!