I accidentally deleted the Macintosh HD - Data partition while trying to perform clean install Catalina!

Give this a try:

Internet/Network Recovery of El Capitan or Later on a Clean Disk

     If possible, back up your files before proceeding.

1. Restart the computer. Immediately, at or before the chime, hold down the (Command-Option-R) keys until a globe appears.
2. The Utility Menu will appear in from 5-20 minutes. Be patient.
3. Select Disk Utility and click on the Continue button.
4. When Disk Utility loads select the target drive (out-dented entry w/type and size) from the side list.
5. Click on the Erase button in Disk Utility's toolbar. A panel will drop down.
6. Set the partition scheme to GUID.
7. Set the Format type to APFS (SSDs, only if installing Mojave or Catalina ) or Mac OS Extended, (Journaled.)
8. Provide a disk name, usually, "Macintosh HD."
9. Click on the Apply button, then click on the Done button when it activates.
10. Quit Disk Utility and return to the Utility Menu.
11. Select Install OS X and click on the Continue button.

Boot into Recovery Mode again and launch Disk Utility. Within Disk Utility click on "View" and select "Show All Devices" so that the physical drive appears in the left pane of Disk Utility. Erase the physical drive as GUID partition and APFS (top option). This will erase all data on the drive.

https://support.apple.com/en-us/HT208496