kotlin or python's kivy for android development?

Answer 1

I suggest using Java for Android development as it is their official and most popular language for development. However it depends on what kind of apps you want to develop. Take a look at this website for languages you might consider learning for Android development:
https://www.androidauthority.com/develop-android-apps-languages-learn-391008/

Answer 2

kotlin is supported in Android studio.....