To disable the Top Bar is very easy and there are actually 3 different ways of doing this:
Disable Globally via Customizer
If you want to disable the Top Bar globally (on your whole site) you can do this in the WordPress Customizer under Appearance > Customize > Top Bar > General
Note: You can also use the Visibility setting in this same Customizer panel if you wanted to simply hide it for various screen sizes.
Disable Conditionally via Page Settings
If you want to enable/disable the Top Bar on your whole site but disable/enable it on certain pages or posts this can be done via the Settings Metabox located at the bottom of your page or post.
Disable Via Child Theme Code (filter)
There is also a filter available in the theme named totaltheme/topbar/is_enabled which you can use to enable/disable the top bar as needed. For example if you wanted to have the top bar disabled only for a specific post type on your site you would need to use the filter in your child theme as this is a very specific modification for your site. You can view a sample snippet for using the filter here.