[Theme Horse Support Team]

Hi Emi,
If you want to set the blog page in blog large image template then select the template in blog image large from you page. Then it will display blog image large.
To select the sidebar go to the Dashboard -> Appearance-> Theme – Options -> design options -> default layout options.
Check here is your sidebar is right or left. Its right sidebar by default. After selecting it you can see the effect of left , right sidebar.

Hope this may help you
Thank you!