Hi,
In WordPress, the “blog” special section is designed to display latest posts regardless of other attributes (categories, metas, authors). There are no built-in filtering options for this section, but there are plugin that can add such filters.
Concerning journal posts, it depends on how those are created. If those are just regular posts, then simply creating a category page would limit the list to posts belonging to the specific journal category. If those are a separate custom post type, than those would need their separate frontend code (dedicated templates) to handle their display.