Apple News + Icon

The Sidebar is nothing more than a shortcut to the actual program.

Use the Go menu in the Finder to select Applications, and you will find the News program inside of there. You can drag it to the sidebar if you want instant access to it.

Apple News is just called "News"

It has the above icon, and is found in the Applications folder, where I indicated.

Use View menu -> View as List

Then View menu -> Sort by name

to locate it alphabetically.

So it would appear the program either was deleted by mistake or moved.

Use https://www.devontechnologies.com/apps/freeware EasyFind to locate it on the hard drive in event it was relocated.

You will be searching for files and folders named News.app

If it can't find any on the whole hard drive, you'll need to reload it with a system reload.

command-R allows you to reload the existing system from startup. Only do this after backing up your data.