I do recommend you should learn both to help you gain experience to tackle different problems, many workplaces lack programmers of those experiences. It's like a triathlon that we aren't made to learn only one language.
Likewise, I like the concept to encourage learning 8 languages rather than 2.
https://www.kickstarter.com/projects/834569564/codescontext-...
RE Java/JVM just try Clojure for a bit... it's really rather good.
Otherwise, do Go. Really useful for high performance. Channels are easy as pie for concurrency. Web services, command line tools, etc; lovely. Downside is that it's verbose and if you hate loops then there's no salvation for you.
Perhaps both together.
[1]: https://www.scientificamerican.com/article/the-interleaving-...
Did you already work with any another programming language (are you beginner)? And which problems do you want to solve? Without answering these questions, there's no chance that you get a helpful answer.
Why you do not like Java? Does Kotlin solve some of those problems?
What are you looking to do with said new language?
Go... or maybe Elixir ;)
Why not Erlang?
Or dart and flutter - all 4 being supposed first class citizens at Google.
My personal philosophy has been to solve/implement the issue at hand using a language that I consider to have "native" proficiency. Because, the list of languages propping up claiming to be the next best thing is large: 1. Kotlin 2. Go 3. Dart/flutter 4. Rust 5. Swift 6. Scala 7. Haskell 8. F#
The advent of llvm has drastically cut down the time to market for new languages. I'm certain a few more will get added to this list soon, so just get the job done following best practices and without incurring technical debt. This will make your work language proof