No internet connection

I switched internet providers, and I'm trying to set up my new network. When I go into settings to turn on my airport (MacBook Pro). I try to connect to airport and it was not recognize my new network and password. I have entered it correctly. It's actually quite slow when I do this procedure even though it's not an internet procedure. My computer takes forever to perform this and then I can't connect. I've tried rebooting and that doesn't help. Any suggestions?