How do I change the name of an Album from unassigned to its correct name? That too seems impossible to do after hours of trying.
Here's one way. Hover over an album's artwork, and you'll see some clickable-links appear. One of them is File. This will open the file list below, where you might find it easy to see what's going on. Or you can just double-click the artwork to open the file list.
Select your album's files in the file list. Right-click and Rename
*. Now you can change the values.
Alternatively, you can use the Action Window > Tag.
* Rename is a very poor and unfortunate choice of terms. It is a hold-over from Windows, and as a verb, it does not properly provide an unambiguous context for what you are doing (are you Renaming the file, or renaming some item?). Its meaning is confounded because it is immediately above Delete, which operates on a File, and immediately below Tag which operates on neither, but is what you're doing when you use Rename, yet Tag is in another section above. Both Tag and "Rename" should be in the same section. The term Rename should be Edit Property or Edit Tag, and Tag should be Toggle Tag Window (or shorter).