@Scourge I used JavaFX for my GUIs, however that takes a little bit of time to set up and a little more experience with GUIs.
If you're interested in starting out with JavaFX, here's a great tutorial.
https://www.runemate.com/community/threads/javafx-for-beginners.1332/
Other than JavaFX, java uses something called Swing. It's a lot simpler, however the GUIs you make are not near as customizable.
With swing, you can literally just create a new class, extend JFrame and then create JObjects (JComboBox, JButton, etc.) and add them to your JPanel.
You'll have to look up a tutorial on both, in short though, Swing is easier to learn than JavaFX with the lack of some functionality.
P.S. I can send you an old Swing GUI I used for a cooker.