Hi, so I want to get into Android App development.
I know the basics of Java and I have already written some simple apps with Java.

However I would like to get more serious with it and now I wonder if I should directly start writing apps in Kotlin or if I should write them in Java.

There are currently more tutorials/docs/SO answers in Java, just because it's been around so much longer for Android, however, Kotlin is a much better language (in my opinion) so it would be good to learn. The good news is you can you them both in the same project if you want to so it honestly doesn't matter. The important thing is just to start!

@ryanmhoffman Kotlin compiles into Bytecode, right?

@404response that is correct.

Java, it’s not going anywhere. There’s many more resources and kotlin (for at least a few more years) will just be bonus points to employers, and yes, all jvm languages - including kotlin, compile to bytecode

@ryanmhoffman oops, didn’t see your response :/

@calmyourtities no worries, you were spot on with your answer.

Try Udacity courses for Android app developer. It's free and good !!!