If you are connected to the motorola modem, you should be able to login to the configuration using this link.
After you get logged in, click on wireless across the top.
Then click on primary network on the left.
This is where you can set the network name and WPA pre-shared key. There is a checkbox to show key. I would suggest enabling WPA2-PSK setting the encryption to TKIP + AES and entering the pre-shared key of your choosing, which will be the password XXXXX your network.