Have you tried making a new user account and setting up that?
It is possible that whatever the problem is might be contained to something in your personal settings (preferences, Application Support, etc) of the account that you migrated.
A new user account would be the first thing that I tried. You can use Fast User switching to get back to the other user if you need to check something out.
I have not bought a new Mac in, according to @ChrisUpchurch , 9 years and 4 months. I don’t want to migrate but perform a clean install. As it is, there’s already at least 20 years of migration. With Silicon I’d prefer things to be fresh!
Aside from this #600 episode, does anyone have any suggestions or warnings, before beginning?
My current backup is:
I also use Dropbox & iCloud file storage.
I have been googling but not seeing anything current. If you have any sources, that would be great. Even if it relates to this great forum.
I’ve begun verifying & updating software on 1Password. Tragedy if I didn’t have my beloved apps ready for their new home!
Thanks for your consideration,
Nikki
Have you verified that you can boot from your CCC backup?
It sounds like you’re getting a new M1-based Mac? If that’s true, ideally you can keep the Intel one around to make sure that you can run all of your software on the new one, and if you need any license info, you should be able to contact support from the old one, if needed.
Thanks, TJ!
Yes, thankfully the CCC drive is bootable 
And I would check pre-setup.
I wrote down all my apps I want to install how to get them in/where to find them. Luckily I took @MacSparky ’s advice to log them in 1Password.
Roughest part will be re-tweaking settings that I did many moons ago, most while listening to MPU!
But it’s exciting to do something different!
Thanks so much @tjluoma for your comments 
How do you know if your CCC is bootable, TJ? I just did that yesterday. I backed everything up to a SeaGate external hard drive. (It should be about a quarter full).
Great question!
With the backup drive attached, go to
System Preferences.app » Startup Disk
If you just see one drive, like this, then macOS does not think your backup drive is bootable:
If you do see your backup drive, select it. There will be a prompt saying “Do you want to boot from this drive?” Say yes.
Then reboot your computer, because that is the real test.
It will be slower to boot your Mac off the backup drive, but as long as it works, you know you have a good backup.
It is not showing up.
Oh well. I recall you use to be able to boot off a CD. However, my CD player is connected with a dongle.
I can confirm that my bootable CCC drive does not show up in the Startup Disk selection pane, but does appear if I boot with Option held down.
Thank you, John!!! I so appreciate your help!!!
Unfortunately, I wasn’t able to boot from it. It started, then gave the “No” sign and stopped. I assume it’s because I have an iMac Pro, but is something I need to investigate further.
So you might want to verify that you can actually boot from yours, as @tjluoma suggested.
I just got an M1 Air and did the following:
It took 4-5 hours to migrate almost a terabyte — not outlandish given that it was moving that data from a spinning hard drive over a USB 3 connection.
The good news is that Migration Assistant did a really good job with an installation that began back in the Leopard or Snow Leopard days.
