Apple’s Touch Bar comes with a default set of shortcuts, depending on which app you're using. If you don't like the default options, you can add and remove buttons to customize the Touch Bar.
Click File. You need to open a window in an app to edit the Touch Bar options for that view.
Select New Window.
Select Customize Touch Bar.
Click and drag buttons down from the display to the bottom of the screen, bringing them to the Touch Bar. You'll only see the options for your current view.
To move a Touch Bar button, hold and drag it to a different spot.
To remove a button from the Touch Bar, hold and drag it to the far left end.
Release your finger when "Remove From Touch Bar" appears.
(This how-to is based on my experiences and info on Apple's support pages — where the images sometimes come from.)