You can change basic settings (Admin bar, Lightbox, Quick Search, Pagination Type) here. You can also exclude blog categories using this setting.

• Go to Appearance > Customize > General Settings > Basic Settings
• Enable or Disable Admin Bar. If you disable the Admin Bar, you won’t see WordPress admin bar on the top of your website when you are logged in. Blue color is enabled.
• Enable/Disable Lightbox. If you enable the Lightbox, the larger version of the images can be viewed in a pop-up, without leaving the page. Blue color is enabled.
• Choose the layout of your posts.
• Select a Pagination Type
• Choose the excerpt word count
• Check categories to exclude from blog and archive page.
• Click on Publish