This document explains what the name is and how to administer your router so you can change your password. That is with the router directly connected via a network cable. The name is on the sticker. The default password is the 13 digit serial number. Also see link above and text below. Also Google "Manage my Router".
Wireless Defaults: Primary SSID (subscriber-managed) = “DDW365” plus a period, plus the last 6 characters of the Wi-Fi MAC address plus “-2.4G.” Example for modem with WiFi MAC address 08:3e:8e:44:28:13 SSID: DDW365.442813-2.4G
WPA Pre-shared Key = Unique key for each device. Also called the network key. The WPA pre-shared key for the DDW365 is the 13 characters of the modem’s serial number and can be found on the Wireless Primary Network screen.