Disable secondary sidebar for all pages.

Hi,
I’ve been trying to increase the width of my standard posts to the size of the gallery posts on all pages including the home page (in ascetica). However, I have a limited understanding of CSS and just can’t figure it out. I’ve tried to disable the secondary sidebar like it is for the gallery posts but I can’t figure out which template is for the standard posts. I don’t even know if I’m making any sense lol. Basically I just need help eliminating the white space next to my posts. My blog is: studylesscraftmore.com
Thanks!