You can choose the sidebar alignment of the theme from Appearance › Customize › Sidebar Position. This is a global setting that applies to all the pages or posts that contain a sidebar.
However this setting can be overwritten from the Page Parameters box situated under the WordPress content editor of the page that you are currently adding / editing.
Make sure that your sidebar is enabled and choose "Right" or "Left" to align it in the left or in the right of your page content.
