You will need to setup the wireless encryption as that Belkin router does not support disabling of the wireless connectivity. Have you opened the router setup page
http://192.168.2.1 ? Click login and the default password is either "admin" or just press return.
Look for the blue bar with wireless in white on the left side of the screen then under that click security. Here you can select the security mode which should be WPA-PSK, encryption technique set to AES, now enter a string of 63 characters. Anything will do but for the strongest security use letters, numbers and characters such as :@~}{. Write it down as you entered it making sure upper/lower case characters are correct and store safely for possible future use. Now click apply changes.
On the left above security click channel and SSID and untick broadcast SSID, again apply changes. On the left click WAN ping blocking and tick the box then apply. Lastly at the bottom left click system settings and enter a password to replace the default, then set time zone and tick box for daylight savings. Click apply and you're done, though for extra protection you might want to use the free 6 month parental control subscription that you probably recieved. That is directly under the blue utilities bar.
Hope that helps, I'll look in tomorrow morning in case you've had any problems.