Reset Messed Up MacBook Air 2017

[omgwalt]

I attempted to reset my 2017 MacBook Air by following the advice on a website, but I did something wrong. I seem to have messed up the containers/volumes. I don't care about saving my old data. I just want to rebuild the machine to its original OS (Sierra) so I can upgrade to Monterey from there.

Right now in Disk Utility I have the following under Internal

AppleAPFSMedia
Preboot - grayed out
Recovery - grayed out
Update
VM - greyed out
APPLE SSD SM0128G Media

I also have the following Disk Images:
Apple UDIF read-only compressed (zlib) Media
OS X Base System
Apple disk image Media
OS X Base System
Apple UDIF read-only compressed (zlib) Media
OS X Install ESD

I tried running First Aid on the Internal drives.

Running First Aid on "AppleAPFSMedia" resulted in an error, "First Aid found corruption that needs to be repaired. To repair the startup volume, run First Aid from Recovery. Click Done to continue." Under Details it says, "Verify storage system. Storage system check exit code is 8. Operation successful."

Running First Aid on "Update" resulted in an error, "First Aid process has failed. If possible back up the data on this volume. Click Done to continue." Under Details it says, "Verifying storage system. Storage system check exit code is 8. Repairing storage system. Storage system check exit code is 8. Storage system verify or repair failed. Operation failed..."

Running First Aid on APPLE SSD SM0128G Media, I get "First Aid process is complete, click Done to continue." Under Details it shows a bunch of steps that end in "Operation Successful."

Can anyone help me?

 

[DeltaMac]

If you don't care about saving any data, remember that your SSD is formatted as APFS, which can't boot with Sierra.
If you really want to go back to Sierra (which is fine), then you need to erase the drive (the device, not just the volume) changing the format to Mac OS Extended (journaled)
Be sure to change the Disk Utility View menu so it actually shows the drive (choose Show All Devices), then choose the top item in the drive list (with the manufacturer's model info), and choose Erase. Remember to change the format to Mac OS Extended, and name the drive whatever you like, and continue with the erase.
That process would also get rid of all those strangely named volumes, and remove the container, too.
But, if you are simply going to upgrade to Monterey, you would save some steps by making a bootable installer for Monterey (plenty of instructions for how to do that here), and erase the drive using Disk Utility while booted to the Monterey installer. There is absolutely no reason to start with Sierra, when you would be immediately going to Monterey at that point anyway.
Don't worry about getting the APFS format, as you will get upgraded to APFS automatically when you install Monterey.

 

[omgwalt]

Thank you for responding. I'm perfectly willing to go directly to Monterey. However, I feel a little out of my depth here. I'm guessing a bootable installer would be to a thumb drive? I would appreciate a little help finding the right resource here.

 

[DeltaMac]

Yes, can be a thumb drive. 16GB is a good size for that.
(I typically make bootable installers on an external SSD, but I often have multiple installers on one drive.)

Apple has a support article that gives you the steps - https://support.apple.com/en-us/HT201372

 

[omgwalt]

Okay, I think I've got it. Thanks.