There are currently no widgets assigned to the left-sidebar, place some!
Once you add widgets to this sidebar, this default information will go away.
Widgets can be added by going to your dashboard (wp-admin) -> Appearance -> Widgets, drag a widget you want to see into one of the appropriate sidebars.
ROTFL – even a simple guy from Poland like me understand that 😀
Are you REALLY from Poland? Curiousity is havin’ a bad effect on the cat! Tj