How to connect wifi on galaxy y gt-s5360

Hello and welcome to Tom's Hardware Forum.

The SSID is the name of the network you have around your router and the security key, which is the same one you used when you connected your computers to the network. Connecting the Samsung mobile will not be by wireless - it will be by tethering using a USB cable and the option wlil appear when you plug the phone in to the computer.

Using the phone to create an Internet connection for the computer to share is another issue so post back if that's what you want to do.
 
An SSID is the name of a wireless local area network (WLAN). All wireless devices on a WLAN must employ the same SSID in order to communicate with each other.
The SSID on wireless clients can be set either manually, by entering the SSID into the client network settings, or automatically, by leaving the SSID blank. Some newer wireless access points disable the automatic SSID broadcast feature in an attempt to improve network security.

SSIDs are case sensitive text strings. The SSID is a sequence of alphanumeric characters (letters or numbers). SSIDs have a maximum length of 32 characters.