How can I find my IP address - not my company's router, but my local machines
I can't believe nobody has suggested the simplest method of all, only 2 clicks (or 3 if your adapter isn't at the top of the list).
Click System Preferences, click Network.
It will display the IP address of the adapter under Status to the right of the network adapters. If your device isn't at the top (which will be the default selected) then simply click on the one with the green status. It's going to be either Wi-Fi or Ethernet.
I used:
ipconfig getifaddr en1