How to resolve Migration Assistant issue with multiple volumes on Mac?

I have a 2019 Intel Macbook Pro with a 4TB SSD that is on AppleCare. I also have a 2019 Intel iMac. Both are running Ventura 13.7.5. I wanted to update the laptop to match the desktop, so I used Migration Assistant. When it finished, the laptop just kept restarting and restarting and restarting. I restarted it in Terminal mode and looked at it from the iMac. It had two volumes, one called Macintosh HD that had very little in it but folders for Applications, Library, System, etc and another called Macintosh HD Data-Data that had most if not all of the transferred material. I tried Disc Utility to repair and it failed because there were multiple volumes (even when one was unmounted). I tried erasing everything and it failed. I unmounted the Macintosh HD volume and it disappeared along with the hard drive icon on the iMac. Disk Utility still sees a Macintosh HD external drive that contains Macintosh HD Data-Data. The only other option I have is Carbon Copy Cloner, but it only sees the Data-Data drive. Not sure if that will work or not. If it doesn't, what else should I try to get my laptop back working?

[Re-Titled by Moderator]