Java swing application window opening sequence

Im beginner in Java Swing. So dont judge me plz :)

I create 9 windows, which are mainscreen, sign,signup... I design GUI and other sources codes as well.And they all have a main function because i created windows as Application windows.(or Application Form , all of them). So how can i set initialize sequence. For example when program runs start with MainScreen then other screens according to ButtonListener(which i created these). Again, my question is how can sure, when program start, it starts in MainScreen. Also another question is How can i put in form like program_name.exe