To connect to the WiFi look for a sticker on your router that will have the Router SSID printed on it along with the password. (The SSID is the name of your Router. It will start with GNX followed by six digits).
On your device (computer, smartphone or tablet) open the WiFi connections and look for your Router's SSID in the list.
Click on the SSID and you will be asked for the password. Enter the password you found printed on the sticker on your router and Join the WiFi network.
Your device should connect to the WiFi network.
Usually devices remember these details so each time you are in range of your Router it will connect automatically.