So I have it configured for Categories to be the first thing a user sees when they log in. When a user creates an account, the categories page is blank even though they have permissions and can post to these categories. Is there a way for by default a user to see all the categories they have permissions to see/post show up on their own
Yeah, by design, Discourse will hide categories that still have their default description from the Categories page. You can still post topics into them, they just do not show up on the Category Listing Page.