Where do I find my IP address?

Settings>WiFi, click on the name of your network then the information symbol on the right (circle with a letter i)

This page shows you how to find your phone's IP address: https://www.whatismyip.com/how-to-find-your-iphones-ip-address/

Note that this is the local address, often begining 192..., which is allocated to local devices by your router or modem. It is not the address by which your router is seen by the outside world. For that you will need either to go to your router's settings, or to use an app or a web page to detect it. This web page will show you the external (WAN) address - http://www.ipchicken.com/