Whoops

On the Mystique theme I got a notice that a second side bar was activated. I tried to deactivate it but instead I deleted my side bars. Under editor they give you all the sections so you can modify them. Well I went to side bar and there was all this coding that included the words 2nd side bar several times so I erased it. (can you tell Im a rookie)? not what I wanted to do – anyone know how to fix this? I just want to return it to how it was and also learn how to deactivate the second sidebar.