Move left sidebar down

I was wondering if there’s a way to move the left sidebar down in the Nirvana theme? As you can see on my website here: https://www.djurskydd.nu the sidebar is covering the top menu and I want to move it down to where it says “?ppet Hus” so I can put in links with pictures with companies I support. Is there a way to solve this without messing with the theme?

Every help is extremely appreciated!