How to have the same layout on pages, single posts, index, etc.

Hello all, sorry if this has been covered already but I can’t seem to find the answer anywhere…

I am trying to build a site starting from the Twenty Eleven theme. I duplicated the theme folder and created a child theme. My question is, is there a simple way to have the layout on all the pages exactly the same? I.e. on the “main” page, which currently has the list of all the blog entries, there is a sidebar to the right, but then if I click on a single entry, or go to a Page, the sidebar disappears. I have tried adding the php for get sidebar at the bottom of page.php (just as it is in index.php) but it places the sidebar below the main content rather than on the right. I know this all probably has to do with the CSS layout stuff, but I guess what I’m asking is, can I just get say, the index.php file working the way I like in the child theme and then have the whole site work the same? If there was no page.php or single.php files in the child theme folder would that do the trick?

Sorry if this sounds a little vague but I feel like I’m getting more and more confused and I imagine there must be a simple solution here. Thanks for any help you can offer!