There are plenty of Java examples out there. How does a beginner try them out with an IDE like IntelliJ? Here's one attempt at showing how it's done.
Assumptions: I'm assuming that you've already downloaded IntelliJ and have Java 14 installed, as well as the JavaFX library.
Sources:
https://drsmith.blog.yorku.ca/2020/10...
https://docs.oracle.com/javafx/2/char...
https://stackoverflow.com/questions/8...
https://www.tutorialspoint.com/javafx...