Need help getting WiFi from this phone to new phone

If you’ve migrated your data from one iPhone to another, that should migrate the password.

If you use iCloud Keychain, that’ll transfer the SSID and password for you.

If you’re not using iCloud Keychain and a not-ancient iOS, you can share the password manually:

How to share your Wi-Fi password from your iPhone, iPad, or iPod touch - Apple Support

Look on the label on back of the router.

Reset the router if necessary .