mac air starts in question mark flashing

A next possible step that could help, would be to start into macOS Recovery and repair the disk.

Instructions on which portion to start with, vary by age of your Mac's system; newer ones are

said best to begin with furthest container or last one, away from the main physical hard drive.

Perhaps idea in itself, is best overall; especially where many items listed, may add confusion.

If you've not gotten anywhere, maybe need to consider a force-quit/restart, or power-off + restart.

• How to repair a Mac disk with Disk Utility - Apple Support

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

This is rather lengthy, and tired eyes may wish for better or faster resolution.

To assume you've read this support article, and attempted suggestions 3x?

• 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."