What are the websites for learning Kotlin?

Question

Java

Hello friends! I am an android developer. like many others, I heard about kotlin, and I had 2 questions:
1) should I switch from java to kotlin?
2) what sites can you recommend for studying? to have less water, more practice, etc. like start android for java. Thanks in advance for your answers

Answer 1

0) You're not an android developer yet
1 ) No, you shouldn't switch to . You need to know Java and it is worth studying Coltin in parallel
2 ) To begin with Kotlin Koans
3) Start android is not about Java, but about Android.

Answer 2

https://github.com/JetBrains/kotlin-examples
https://kotlinlang.org/
https://kotlinlang.ru/

Answer 3

https://stepik.org/catalog?q=kotlin