When you post use the "type" dropdown to make it be a "page" instead of a "post", then make sure you have the appropriate widget selected for that container. Sorry, but I don't know off the top of my head what that widget is called.

I found.
I used the widget "Post list", I setup like this:
- link to block: checked
- order: oldest to newest
- Display: 1

I wrote an article with title "About this blog" I changed the date so the article is the oldest one.

When you write your entry in expert mode select "Page" from the Type field. This will cause it to be treated different than a post. It will not show up in the normal flow of posts. The name of the widget that shows pages (not posts) is "Page list", though you've found a method that works so it's all good.

I do not know what the post type "Link" does for us. Possibly it is an idea that has not yet grown into a feature?

THANK YOU very much EdB. Now I understand why we can choose page when editing an article.