what kotlin normally used for and what are the benefits of learning it

Answer 1

kotlin is android development language ,kotlin is so advance you can do all things in few lines which can take many line's in java
https://www.sololearn.com/learn/7792/?ref=app

Answer 2

This could generally help:

https://www.infoworld.com/article/3224868/what-is-kotlin-the-java-alternative-explained.html