News comes with OS install, so, not in Mac App Store.
When you say can't find it, not in the dock AND /Applications?
Might try re-installing Catalina: will keeping existing files, settings in place, but will overlay missing pieces.
Or, wild guess, maybe tied to region/country settings (ie. country that does not have Apple News)? But guessing should still be able to see it in /Applications even if region does not have News.