Difficulty getting my site to sync

I have WPMU DEV loaded, locked and set up on my site, according to my way of lookin' at things. The dashboard plug-in is uploaded and activated, I can access my hub, community forum, plug-ins etc. but I am unable to access the sign-in page for my Dashboard. I am using an Ocean WP Theme with WordPress 4.8 ???. I am an absolute 'Technophob' and a Komputer Klutz added to being a WordPress Newbie. I was kinda hopin' that someone would be prepared to assist, so I don't waste my free trial, not connected.