kotlin is different enough that you can go into learning it without any knowledge of java.
You're biggest difficulty might be some more higher level functionality that requires a deeper understanding of the JVM, but java wouldn't teach you that any better than kotlin would.
If you haven't tried it yet, check out kotlin koans:
https://kotlinlang.org/docs/tutorials/koans.html
It's a great resource for beginners, and teaches you fundamental things that will help you succeed in learning how to use Kotlin.