My Ipad 2 won't connect to my WIFI !?

I just bought the ipad2 3G&WIFI I didn't get the 3G sim card yet , so I'm trying to connect the ipad with the wifi but it says that its unable to connect I've tried EVERYTHING !! resetting , restarting everything you name it ! my friend said that the same thing happened to her with the ipod long ago so she can't remember how she made it work , anyone has faced this problem please tell me what to do :''( !! *Thanks*