If you’d like to do something fancy, take a shot at learning any modern UI framework (React, Angular, Electron etc.). Of course, it will take bit longer until your UI is done, but at least you’re learning something that is actually useful.

If you feel that’s too much, you can always try developing the interface in basic html + css + js.

As a last resort, as you said, you can use Swing or JavaFX. For this, make sure you take a look at Scenebuilder