If you mean your IP that your hotspot is being assigned by your mobile provider, you can go to our homepage and get your IP.
If you mean the IP that's assigned to your hotspot as a local device, you can go into your hotspot settings. You should see something like 192.168.1.1. Another option for Windows is to do Start Run CMD. At the prompt, type ipconfig /all and look at the Gateway IP. The Gateway IP will most likely be the IP of your hotspot.