However, in case if you have a wired HP Printer. Then, either you can directly hook it up to your Network Access Point(Router) by means of an Ethernet/ LAN Cable. Else, you can use a USB cable to connect it to your computer.
If you have purchased an HP Printer and you are confused about the 123.hp.com/setup then this information is for you. Read the full procedure here and follow the easy steps. For more info:-
HP Printer Drivers
HP Printer Download