In discussion with the designer about how he would initiate this move, he told me that he had never moved a “multisite” installation before and didn’t know how. This was the first I had heard of it being multisite and I did not have any experience with that either. (Not to mention that multisite is not appropriate for this instance)
The codex was very helpful for this. Once I was able to turn off the multisite, the factors I needed for the move showed up in the settings and I will be moving the site later today.
Thank you for your reply.
I managed to do that by getting the page id of the page I wanted to show at the opening, going to menus and adding that link to the ‘home’ page block.
Mantra should be mobile friendly on its own but if you’re having problems, use one of the mobile detect plugins available from Word Press.