Not sure what I did, but I went to configuration and thought I retyped everything the same again, and now it’s working. To answer my own questions (for future searchers):
Do I just open today’s note and scroll down to see previous days?
No, it creates a new file (whatever you named it in the configuration). This file will reside in the Journals folder (or wherever you keep your journals).
Or is there another file called Journal that is compilation of all of my thousands of notes?
As mentioned, the new file is a compilation of all prior notes. Actually it is a list of links for each day, rather than the text themselves (which is the better way to do that).
Kinda nice, for those that used to use Logseq or just like scrolling up and down the days.