Installed…then when trying to access goes 'Page Not Found'

Hey, i’m new to the WordPress stuff and need some help. Once I installed www.remarpro.com on one of my WordPress.com blogs using Fantsacio it says the installation completes and should work at the domain i.e. https://www.domain.wordpress.com/wp-admin but once I go into that link all that comes up is 404 Error Page Not Found? and directs to the page of my blog saying that. Can anyone help me, or had the same problem before?!