You can change your Zotero data directory from the Advanced → Files and Folders pane of the Zotero preferences.

Once you've selected the new location and confirmed that all your data and files are present, I would recommend deleting the new folder in the default location to avoid future confusion.

I followed instructions and successfully moved my Zotero directory.

I would add that there were two directories that needed to be changed. One, called "data", seems to contain the entire Zotero user database, the subject of my query. The second, "linked files", I am inferring, holds actual documents (to what the data links). Anyone needing to move the directory might create these new directories before opening Zotero and following the instructions given above. (Do I want to find and copy the "linked files" also?)

Since reassignment of the directory requires the user to copy Zotero database from the old location to the new location, why not just perform the copy operation before entering the preferences dialog?

Finally, here is the location of this preference:
Edit>preferences>advanced>files and folders.

Thank you again for your help.

I am a novice and appreciate the help you have given. I don't want to add confusion. I just want to clarify what I meant for the benefit of people who need to do what I wanted to do.

It seems I did not follow your procedure exactly, because I never needed to delete a new directory. I just made a new directory where I wanted it, named "Zotero", entered Edit>preferences>advanced>files and folders, and told Zotero where to look for my data files. Zotero was then looking at an empty folder, which was a little scary. Then I closed Zotero, copied my data files over to the new folder, and then re-started Zotero, which then recognized all of my data in the new location. Naturally at this point I would not delete the new folder, but the old folder. I don't know where I deviated from the path you suggested, but it seemed to work. I am glad it did, since I obviously don't know how to follow instructions.

What I was suggesting, or asking, is whether I might have simply copied my data directory from the old location to the new location, and then simply told Zotero (Edit>preferences>advanced>files and folders) to look in the new location.

Yes. But you don't particularly need to copy your entire Zotero data directory — you can just move it. It doesn't really matter in the case of moving to another drive, but if just moving to another location on the same disk copying would be much slower than moving. And if you moved first, Zotero would then create a new empty folder in the default location before you told it to use the new location.

Another approach would be to create a new empty folder in the new location, point Zotero there, move the files from the old folder to the new folder, and then delete the empty old folder.

There are various ways to do it, but it doesn't really matter. In one order or another, you just need to have all your files in the new location and to have Zotero pointing at that location, and you want to make sure there are no extra folders around to confuse you later.