Two Disks - one of erased data showing in Disk Utility.

Nothing has been erased since both volumes contain data. The only thing I see is someone renamed the "Data" volume as "Erased HD".

Within Disk Utility click "View" and select "Show All Devices" so that the physical drive appears on the left pane of Disk Utility. Select the physical drive and erase it as GUID partition and APFS (top option)....this procedure is for Intel Macs only. Quit Disk Utility and select the "Reinstall macOS" option.

You neglected to mention the exact model of this Mac. If you are accessing recovery mode, then I would highly recommend you first create a bootable macOS 10.15 USB installer if you can still boot & log into this Mac. We have received reports that Internet Recovery Mode has not been working for many people and we don't know whether it is just affecting certain older online installers, or just certain older models of Macs.

Create a bootable installer for macOS - Apple Support

FYI, here is an Apple article with instructions for what to do when selling or transferring ownership of a Mac (the "seller" needs to make sure to disassociate their AppleID & iCloud from the Mac before performing a clean install of macOS):

What to do before you sell, give away, trade in, or recycle your Mac - Apple Support

To my eye, the setup appears to be fine but for a Data volume with a rather poor and off-sync name. It appears the Data volume has been, probably manually, renamed.

Starting with the release of macOS 10.14 Mojave, the Mac uses an APFS hdd/ssd format which creates two almost identically named drive volumes. The startup drive contains the critical macOS System files and is usually named "Macintosh HD". It is identified by the Mac Finder icon in your Disk Utility screenshot. Your Home folder and User files will live on the volume named "Macintosh HD - Data", the one with the House icon.

It is possible to manually change the names of the drive volumes using Disk Utility and cause them to be mislabeled with regard to each other, but I don't believe it affects the performance of the computer.

If the computer is working properly, you can ignore the naming of these volumes, but you must not attempt to erase either or both unless you have backed up your data and are prepared to reinstall the macOS from Recovery mode or a bootable external drive.

If the laptop's hdd is displayed on the Desktop, you can select the desktop icon, press Enter and rename the drive and see if it properly changes both of the names as it should. No real harm will come from changing the drive name, and the one that contains your user files should always have the -Data suffix.

You're welcome. 🙂

I should add... if you double-click the bolded volume name there in your Disk Utility window, you can rename each volume. For the sake of normalcy and convention, I suggest changing the name of "HD" to "Macintosh HD". Rename the other "Macintosh HD - Data" (without the quotes).