Java GUI

I'm trying to create a simple GUI program that will display a combo box that will change the font style of the title when selected. 

When I run it, the output says build successful but nothing shows up. I normally set the visible to true but it's not working this time. I tried setting the visible to true in the main method instead but nothing came up.

I've attached the code onto this post in a word document.

Any help is appreciated!