How do you find your iPhone Wi-Fi password and change it?

See this Apple article: If you need help with your Wi‑Fi password

https://support.apple.com/en-us/HT204070

As razmee209 has already mentioned, the Wi-Fi password would have been configured on the wireless router. We are assuming that this is your home network and that you would have administrator access to this router.

If so, you basically have two options:

1. Review the owner's manual for this router on how to access its administrator web page to access the router's wireless settings, OR
2. Reset the router so that it clears out any existing configuration settings, including the router's passwords.

Thelm3230 wrote:

How do you find your Wi-Fi password and change it?

Log on to your router of wifi provider page and change it that way. IF you don't know how contact your wifi provider.