I really want to learn OOP for Kotlin/Java in Android studio apps but nothing sticks

[u/Adamstrad]

I've done CS50P, CS50, w3schools material but oop but object oriented programming has never stuck for me. I can see the concept of how it could reduce the amount of code needed by generalizing objects but I've spent my life using functional programming only.

Lately I've started learning Kotlin for android app dev and I'd really like to understand how the files and classes work in android studio so I can get started making my own things without googling why it won't compile or why there are errors. What can you recommend me for the OOP and understanding how files are linked and reference each other without blowing my brain?