check on the router that wifi port is turned on. and is sending a ssid id. most people change the router wifi name to somethng called home or a name they know if there more the one wifi that gets picked up. also when you set up a wifi for the first time it ask you to put in a wep key. this is a password that you need to write down or you cant log into the router without it.
or for convinience.
hold reset button on router till it restarts then use login info on sticker to connect to wifi (change admin pass though)
this way you always have the password on the sticker on the router