I have done little Android development and none in Kotlin. However, if it is anything like the Obj-C to Swift transition, then I would recommend to learn to wri

I have done little Android development and none in Kotlin. However, if it is anything like the Obj-C to Swift transition, then I would recommend to learn to write programs in Kotlin but learn to read Java code. Most examples/tutorials/solutions will be in Java so you definitely need to understand them. However, I think it is better to write all new code in Kotlin.