Welcome willorge!
Could you please shutdown aMule, download a server.met file at ed2k.2x4u.de and then save it to ~/Library/Application Support/aMule and start aMule again? (~ is your home-directory, like /Users/willorge)
Then please try again to connect to a server. If this still does not work: Do you have any router (/this airport-thingy) or firewall in use? You have to open/forward some ports in this case. (Usually 4662TCP and 4665+4672UDP)