If you have a printer already installed on your Mac, but you just want to find the IP address, this is one quick way to do it without printing out a test page and wasting paper / ink.

Click on the Apple logo and then select About This Mac.

Click on System Report….

In the left-hand column, under Hardware, select Printers.

Find the printer you want more information about, and then click on that printer. You should see the IP address next to URI.