help with netbeans

I want to open the Dialogclass "Übersicht" from the Dialogclass Login. I found the method startÜbersicht() but I don´t know what I have to put in which class. I have a Javaclass Account(with get und set), javaclass DBAnbindung(extends to Account and has method get data base and show information from the data base)
What I have to do that this works?

I am 12 years old and wat is this