What about the categories I’m adding to my posts? Are they just for show, or can I generate category counts and pages?
you can do most anything you want with tags and categories, though you have to make the page(s) - jekyll doesn’t auto generate a category list page or anything.
Here is a random google search result of an example:
(I changed this from my initial link as the more I read that link I wasn’t sure I liked it)
I’m not particularly sure what you want to do so not sure what else to tell you. I think there is a plugin that can do a lot, but I have never used it.