There are currently no widgets assigned to the right-sidebar, place some!
Once you add widgets to this sidebar, this default information will go away.
This theme also uses the WordPress 3.0 Menu system. You probably see the default stuff you have in the menubar. Go to Appearance -> Menu in the wp-admin (dashboard) and create a new menu.
Eigentlich heisst es ja „idisco“.
Richtig! Ein großartiges Liedchen! 🙂