Which one should I learn, JavaFx or TornadoFx?

It seems that TornadoFx is just a Kotlin version of JavaFx. I suppose this depends on what your goal is then. JavaFx will be more widely usable, and can be used in future Java projects without the need for the Kotlin-wrapper. You can always learn both (which you might do automatically when learning TornadoFx, as it is based on JavaFx)

@eldamsheety https://edvin.gitbooks.io/tornadofx-guide/content/1.%20Why%20TornadoFX.html

Thank you

No problem. If you have any questions, the #tornadofx channel is full of really helpful people.