Use Wi-Fi on cell phone without a service plan

Yes, this should work fine. I have an iPhone 13 without a SIM card or service plan and it can be used like an iPod or small iPad. You will always need a WiFi connection though.

Do you mean WiFi to call or WiFi just to use your phone like an iPod for music and such? If you mean WiFi for calling without a plan, then no. If you just want to use it like an iPod, then yes.

Is this a question?

You put a question mark on the end so I assume you meant it as a question.

Yes, you should be able to do that.