Erm. Well.
You see the button on the blue menu bar that says "Make a Comic"
well............
click it.
you'll be presented with 3 panels, and a bunch of boxes underneath, including pull down menu's. use these to change the characters, background etc. The text boxes under those control the speech for that panel.
I dont know really what else I can really tell ya., Im sure someone else will pipe up with a suggestion or two.