What I need to learn to make a Java GUI mixed with website? [closed]

So I am currently studying Java in Udemy from Tim Buchalka. Yesterday, I downloaded the Pomodoro desktop application from focusBooster. Now I wonder, If I am to make an app like this where I have the JavaFx GUI of Java that needs to be online to sign in. Then the information should be updated in your website account as if they're synchronized (app and website). What are the things that I need to learn if I will be using Java? I've heard of JSP but confused how can I combine JavaFX to JSP? Or is JavaSE alone enough to make this kind of application? Please please somebody help me!