To set the site layout and loader navigate to:
Dashboard >> Appearance >> Customize >> Site Layout
You will find the corresponding option inside
- Site layout –
Allows you to select site layout full-width or Boxed-layout.
- Max Content Layout Width –
Allows you to set site content/container width.
Site Loader : –
You have the option to enable or disable the same, it will allow you to show loader before loading content.