I used the Editor tool to add a new record to the existing attribute table of my shapefile.
But when I save my edits, it doesn't appear on my map. In theory, it should be a point located to the upper left of Conway.
I read this answer that told me to calculate the geometry for my coordinate fields, but when I do that, I just get "null". What am I doing wrong...?
You are going to want to use the Create Features window, accessible within Editor -> Editing Windows.
Here you can create features similar to the features currently on the map.
Once you are done drawing the feature, it will be added to the attribute table where you can edit whichever attributes you need.
It looks like you didn't actually place a geometry using one of the 'standard' methods, so you've got a record with a null geometry. You should delete that record, save your edits, then re-attempt adding a new point geometry using the 'Absolute XY' method (start a new edit session, right-click in map, select 'Absolute XY' and place your new point using the XY coordinates).
