when activating personal hotspot on iphone 12, should my wifi be active or turned off ?

When turning the Hotspot ON then your Wi-Fi should also be set to ON. What this does is that the iPhone creates a small Wi-Fi network that other devices can connect to (your hotspot). If you forget to turn the Wi-Fi ON on our iPhone the it will remind you to do so as well.

Axel F.

It needs to be on. If you have it off, it will turn on when you turn your Hotspot on. WiFi is what is uses as the Hotspot connection so it needs to be on.