I'm not trying to pass the buck, only trying to direct you to the channel that will best help you to get the results you are asking about.
cafe commerce is a php application that gets added t your domain. To have the cafe commerce php application added to your domain, you will need to contact the hosting provider that manages your Domain, in this case Dreamhost.
SSL Certificates also, are managed by the hosting provider that manager your domain.
If you contact Dreamhost support, they will be able to help you with these Domain specific issues.