The default location of the folder containing the master catalog and previews is a sub folder of the System Pictures folder . That folder is called Lightroom. Restore that folder to the Pictures folder.
The folder containing your images folder should be restored to the new NAS.
Once done, when you open your master catalog file in Lightroom, the images folders will be indicated as missing. This is because they are now located on a different volume.
In the Lightroom Classic Folder panel, right click on the top most level missing folder and choose "Update folder location".
FWIW, you do not need a NAS. And you do not need RAID, Especially RAID. What you do need is a system backup app like TimeMachine running constantly as a background task to back up all of your critical data to a dedicated backup volume. Your backup volume needs to be large enough to accommodate all of your critical data on both the Primary disk (MacIntoshHD) and your volume containing your images. If you want to back up to a NAS, I's suggests getting a TimeCapsule from Apple.
RAID is not backup. Any errors that you create simple get replicated to all of the RAID configured disks. If you accidentally delete a file on the RAID drive, it is gone forever and not available on any backup volume unless you are running a system backup app. If your RAID package runs a proprietary file system, when the RAID Controller fails, you will lose access to all of your data stared on the RAID disks until you replace the RAID controlled with an identical RAID controller that can read the proprietary RAID filesystem.