Toolbar management in macOS High Sierra 10.13.6
In my iMac (late 2013) I can't manage the toolbar view in System Preferences - Dock doesn't have settings for the toolbar
iMac 27″
What are you calling the toolbar?
The translucent bar with the icons and trash can is properly called the Dock.
If you are talking the left sidebar of the Finder, that's managed under Finder menu -> Preferences.
If you are talking the portion of the Finder window, on the top of the menu that actually is called Toolbar, that's managed from the View menu of the Finder under Customize toolbar.
If you have a MacBook Pro with a touchbar, there are system preferences for that.