Port forwarding help please?

I am trying to port forward to play multiplayer Terraria by following the guide on portforward.com. I am setting a static IP address. But when I look up my IP address, Default Gateway, and DNS in the command prompt, they all look really fake, like just 10s and 0s or 10.0.0.2 The website says that if the Default Gateway and the DNS are the same, which they are, then I need to log into my router's web interface and look at my router's status page, but I don't know how to do that.