You need to know a IP to connect to in the first place because of the peer to peer network,
try one of these: gnet2.ath.cx
                  gnet3.ath.cx
                  gnet4.ath.cx
                  gnet4.ath.cx

Fill in a IP adres under gnutella connections, push add and hit connect

Gnutella has its website at www.gnutella.wego.com