That image is from an old version of Godot. The orange rectangle does not appear around collision shapes any more so that advice is not necessary.
What do you mean by "random circles"? If you added a capsule shape, you'll see two size handles to adjust its height and width.
Make sure you're using the current version of the docs:
Note the "3.2" in the URL. You can select the docs version at the bottom of the left column on the docs page. You can also choose "stable", and it will show the docs for 3.2.