My Mac shows a question mark, where do I find the utility disk

Boot into Restore Mode, CMD+r, LOOk forTools or Utilities Menu, In the Disk Utility app  on your Mac, choose View > Show All Devices.

Note: If you’re checking your startup disk or startup volume, restart your computer in macOS Recovery, select Disk Utility in the macOS Utilities window, then click Continue. If you check your startup volume (Macintosh HD), make sure you also check your data volume (Macintosh HD - Data).