Ooh, that's a tough one. Java is my foundation; it's the first programming language I learned in school. Switching to Kotlin was easy (or, easier) because I already had a foundation. Most of it is the same in both languages, with minor tweaks (such as no commas in Kotlin).
Personally, I would say just dive in with Kotlin for Android. It's officially supported, and a lot of stuff is happening with Kotlin in the forefront now. Start with Kotlin. If you find a tutorial in Java, you can always copy and paste it into Android Studio and it will automatically convert it to Kotlin for you as best as it can.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.