If you can’t remember which folder it is, but Lightroom Classic had already imported some of the pictures, the pictures are in the catalog, so there are several ways to find out where it is.
First select any of the photos in the Library module and choose the command Photo > Go to Folder in Library. That will expand the Folders panel and select the folder containing the file. Or, choose the command Photo > Show in Finder. That reveals the photo file in the macOS Finder desktop, in the window of the folder containing that file.
Another way to find that folder is to use macOS Spotlight search to look for files ending in the filename extension of the images that it was importing. For example, if it was Sony raw, do a search for .ARW files.
If you start the search in a window on the macOS Finder desktop, you can refine the search further: You can search for .ARW files imported after a certain date or on a certain date, to only find the files that were partially imported. Then, when it gives you a list of those, use the command File > Show Enclosing Folder to open the folder containing that file. That’s the folder that was set.
When you select one of the search results, the path bar at the bottom of the search results window is another way for you to see where that folder is. So you can also double-click the file’s containing folder shown in the path bar.

With their folder open, you can now move those images to the folder where you actually want them to be. But you might want to do that move in the Folders panel in Lightroom Classic, because if you move them in the Finder then Lightroom Classic won’t be aware of the move and will lose track of them; you’d have to re-link to the new folder manually.
There should be no need to re-sync or re-import. Because the images are already imported, just change their folder location.
Then, make sure to set the cloud sync folder in Lightroom Classic the way you want it, so this won’t happen again in the future. I set my sync folder to the same location and subfolder date organization as in the Import dialog box, so that no matter how the images come in, they are all organized the same way under the same parent folder.