From what I understand you've gone through the process to connect to a specific SSID, you click connect, and where you are to add a password there is no field to input and/or a button to proceed.
If you're able to go access the router you may be able to use the WPA button (might look like two curved arrows going up and down).
You may be able to go into your network settings, which show up at the bottom of the screen, and find the right network SSID.
You might also want to try opening your Network Sharing Centre and manually Setup a New Connection or Network.