By default, the Touch Bar’s Control Strip displays brightness, volume, mute, and Siri options. While Apple thinks that should work for most people out-of-the-box, it might not work for you. Luckily, it’s easy to change.
Open System Preferences > Keyboard, then choose “Customize Control Strip.” You’ll see the options in your Control Strip begin to shake, as well as a number of new options appear on-screen. Review the different options, and, when you find one you like, drag it down to replace one of the existing Control Strips options. You can do the same for the expanded Control Strip; just tap the arrow while in this edit mode.
Another tip: you don’t need to have a fully loaded Control Strip or expanded Control Strip. You can actually drag your cursor “beneath” your display to the Control Strip, where the option will light up. Now, drag it back up to the window, and it’ll disappear from your Touch Bar. Alternatively, drag these options with your finger to the left of the Touch Bar, where you’ll find a trash can ready to remove them.