Hi,
It would probably be correct to assume that this is an HP DeskJet 2700 All-In-One Printer, which is listed in About AirPrint - Apple Support as a supported model.
The first part would be the connection to the wireless network (Wi-Fi router). If necessary/applicable, try WPS (http://h10032.www1.hp.com/ctg/Manual/c06611085#d0e2596).
Once the printer has been connected to the router, make sure that your iPad is connected to the same network.
If the iPad cannot find the AirPrint printer, you could try the following procedure:
Power off the Wi-Fi router, the printer, the iPad, and all other devices/computers. Wait two to three minutes. Power on the router. Wait two to three minutes. Power on the printer. Wait a minute or two. Power on the iPad. Finally, power on all other devices/computers.