Connect the modes's ethernet cable to WAN port on the router. Connect your PC and other devices either via the LAN ports (4 ports) or via wifi after setting WPA2 and any encryption option with a WPA pre shared key/passwd. Leave WAN Ip setings to automatic to receive a dhcp IP from the cable modem, and it ll receive a public IP for the WAn port after a restart/Ip refresh and everything will be set. Save the setings and backup the setings to a file for future restores.