Sidebar modification: Benevolence theme

So this is what I found out when I went to the widgets page:

“The theme you are currently using isn’t widget-aware, meaning that it has no sidebars that you are able to change. For information on making your theme widget-aware, please follow these instructions.”

I do not know how to make my theme widget aware. The blog used to be on wordpress.com and I remember that the appearance options were different. Now I am self-hosting on ready-hosting.

I wonder if I should change the theme or can I change something in the existing theme. I do know basic html but that is about it.

Thank you so much!