Hi Alli6,
Although First Aid may be a good idea, it (as far as I know) deals with disk and filesystem issues. Because the operating system (macOS for the Mac partition) controls what appears on the Touch Bar, I'd suggest reinstalling macOS instead. You won't lose any data on your Mac, provided that you don't use Disk Utility to erase your Mac. Below are two methods for reinstalling macOS.
Method A: Use macOS to reinstall macOS
1. If your Mac isn't already running, boot your Mac normally into macOS. Log in when prompted.
2. When you're logged in, open the App Store and search for macOS High Sierra.
3. Download the installer (it's 4-5 GB large) and wait for the download to complete.
BONUS: You can use the macOS installer to transform a USB flash drive into a bootable installer for macOS. Future installations will be much faster via the installer because it already contains a copy of macOS. More details here: How to create a bootable installer for macOS - Apple Support
4. When the installer is downloaded, it should automatically open. Make sure that macOS will be installed onto your startup disk (usually named Macintosh HD).
5. Wait for the installation to complete. Your Mac will restart a couple of times.
Method B: Use Recovery Mode or a bootable installer to install macOS
1. Boot Recovery Mode by holding down Command-R while you turn on or restart your Mac. Alternatively, if you have a bootable installer, hold down the Option key while you turn on or restart your Mac, and release it when you see a selection of startup disks. Use the arrow keys to select Install macOS High Sierra, then press Enter (Return).
2. When the Utilities menu appears, choose Reinstall macOS. Make sure that macOS will be installed onto your startup disk (usually named Macintosh HD).
3. Wait for the installation to complete. Your Mac will restart a couple of times.
Hope this helps!
