OK, I saw the link for the help video at the bottom - it helped. I have to add a new entity. I was fooled thinking I would already be there and that the entry was me, but it is apparently a general placeholder into which numerous entities can go. For me this was not obvious at all, and I only figured that out by watching the video (which was not easy to spot!).
I'll go through the process now and hopefully no more confusions.