I strongly recommend this course: https://www.udemy.com/course/dependency-injection-in-android-with-dagger/
In one sentence: This course teaches you WHY we use dependency injection, in detail, before HOW.
Do not do dependency injection just because you want to do it. Do not learn how to apply Dagger/Hilt/Anvil/Whetstone before knowing the exact reason you are doing it.
This course takes you through the suffering of manual dependency injection to let you understand how a dependency injection architectural pattern benefits you increasing the readability of your app and keeping your app maintainable.
Only after that concept seeps through you, then this course will introduce the DI tools to help alleviate the suffering.