How to add template to get sidebars in pages?

Dear friends, my present theme (Twenty Eleven) doesn’t add sidebar to pages. I actually created a normal page with the content (test content) you see there, and in settings > reading, I set that page as the home page (https://oshohindi.net/), but as you can see, the alignment of text is not correct & sidebar is missing. So, how do i add the sidebar to it?