Which language should I choose?
If you want a compiled language then go for Rust. It takes a certain mindset to get your head around its memory management system and the way it handles "borrowed" memory. However, it will generate blindingly fast code that you can cross-compile for other platforms. As a systems programming language I highly recommend it. Take time and learn it.
Java is only compiled to bytecode, not to machine code. So it executes in the Java Virtual Machine. DOn't think that its not fast, because the latest incarnation are very fast indeed. For most practical purposes, users of your code won't notice any difference. There are a heck of a lot of features in Java that you either have to import via crates in Rust, or write yoursef. So productivity-wise, Java may well beat Rust.
Kotlin is a Java-lookalike. It's a nice, and succinct version of Java and is totally interoperable. But its a bit niche, and for me it fails because my dev environment of choice (Spring Tool Suite) doesn't really play well with Kotlin. To use it you would be well advised to use iDeaj. I have used kotlin, and I like it, but not enough to ditch all my Java code.
Other contenders, depending on your platform of choice are Golang, C, C++, and C# (available as Mono on Linux systems).
I use Rust and Java and if you need a compiled language I recommend Rust.
I will highly recommend Kotlin. I have worked with all three intensely and so far the development speed and simplicity is the best with Kotlin. Kotlin supports coroutines out of the box. Now, it isn't something that can't be implemented in other languages but Kotlin makes it super easy to work with them. Kotlin has a bit of learning curve, so, by the time you can actually use it idiomatically chances are that you will get proficient in Java too. But once you get it, you get it, then there is no other language ;) Kotlin is backed by Google and Jetbrains team so you can expect latest programming features and good community support.