Screen shows a folder with a question mark

There is a standard reply for this specific issue:

• If your Mac starts up to a question mark - Apple Support

https://support.apple.com/en-us/HT204323

"A folder with a flashing question mark means that your startup disk is

no longer available or doesn't contain a working Mac operating system."

Two things, first.

[May not apply to M1 Apple Silicon.]

1. If the question mark appears only momentarily before your Mac starts up normally:Reset NVRAM.
2. Make sure that your preferred startup disk is selected in Startup Disk preferences.

• IF the question mark persists, follow these steps:

1. Press and hold the power button on your Mac for up to 10 seconds, until your Mac turns off.
2. Turn on your Mac and immediately press and hold Command (⌘) and R to start up from macOS Recovery.
3. While in macOS Recovery, use Disk Utility to repair your startup disk.
4. If Disk Utility found no errors or repaired all errors, reinstall macOS.
5. If you still need help, please contact Apple Support.

(Published Date: May 03, 2021)

• Use macOS Recovery on a Mac with Apple Silicon (M1/M2) - Apple Support

https://support.apple.com/guide/mac-help/macos-recovery-a-mac-apple-silicon-mchl82829c17/mac

• How to repair a Mac disk with Disk Utility - Apple Support (note M1 Silicon* instructions)

https://support.apple.com/en-us/HT210898