Sidebar gone

HI!

After installation my ‘Sidebar’ widgets that I had before installation are not showing on the website. It’s empty. When I add widget in ‘Add Widget After Content’ the widget appears on both parts on sidebar and under content. I don’t want it to show on sidebar but only under posts. On sidebar I want to use just ‘Sidebar’ widget area with widgets I had there before installation. Priority sat to 99.

Thanks in advance!