Ifnots effectively a back up of existing media, why to you want raid 1?

With Pihole off, look for your gateway address. That will be your router address. Are you using windows on your usual pc? Ipconfig command should show you your gateway, easily.

Then tap that into your browser to log in to your router and deactivate dhcp from it.

Omg, thanks for helping me to get the names. The arrs indeed.