FTP help!!!

Hello. I need some help here. I’m trying to setup, in Dreamweaver, the remote site feature so I can start editing my twentyfourteen child theme. I am having trouble with signing in with my host id credentials. I’m assuming they are my wordpress.com username and password and using wordpress.com as the ftp address it automatically wants to use port 21 so I leave it alone. what am I doing wrong? If I’m using the wrong information then please someone guide me to where I can find my host ID username and password or who I can contact to get these credentials. thank you anyone who reads this for their time.

-Brandon