Hi, Lynn -- to create a personal category, this is the help page that gives you the best information:
https://www.wikitree.com/wiki/Help:Personal_Categories
My personal category is simply my WikiTree number: [[Category: Day-1904]]
Beyond that, the instructions aren't quite clear. They say all personal categories should be linked to your code, but then the example they give is simply [[Category: Sample1]].
But if you create something you intend to be a subcategory of your personal category, it needs to be nested under your personal subcategory. For instance, if you create [[Category: George Island Retreats]] as a personal category, then George Island Retreats should be a subcategory of [[Category: Hemrick-3]]