When I open Settings, I do not get a HomeAssistantCloud Tab. I looked in the Configuration.yaml file, there is a cloud: line. What else should I look for?
You shouldn't need a separate cloud: line if you already have a default_config:, since default config includes cloud.
Comment out the cloud line if you have default config, then restart HA just to be sure. If you're still not seeing an entry after restart, then go to the settings page and add this to the end of the url /cloud/login