I understand that each WP site is designed for a single blog. We have created a few private blog pages accessed by sharing the url. We used the Full Blog Visual Composer element and chose “Select A Specific Category” as this private blog has only one category. For example:

https://planforaction.com/2019-review/

1. We have been constructing a public blog with multiple categories: https://planforaction.com/ideas-and-news/
This is created using the Secular Settings,>General Option,>Select Blog Page “Ideas and News.”
We created the sidebar using the Sidebar Blog widget and selecting “Recent Posts” and “Categories.”
By using this method, ALL categories appear,  including the private ones. And we don’t want that.

Is it possible to use the Full Blog Visual Composer element and chose “Select A Specific Category” IF we have one Parent category for Ideas and News with the rest of the categories we want to appear as Children? And, if so, how do we set up the Sidebar Blog widget or do we need to create a custom sidebar?

2. In followup to the above, we would also like the category name to appear with each individual post. Is there a way to make this happen?

Look forward to y0ur advise.