You can find the Sidebars option in the theme Customizer on Appearance → Customize → General → Global Sidebar.
Sticky Sidebar (Pro)
You can choose whether the left sidebar or the right sidebar or both sidebars are sticky or not.
Sidebars sticky from the bottom or stick to the top and the distance when sticky.
You can choose from different sidebar layouts for Page, Blog post, Blog post archive, Search and 404 page etc… When all individual settings are not selected.