Can't find common apps in the app store for my Macbook

First, I'm a new Macbook user so I'm still learning my way around. But when I try to find common apps for my Macbook for example, Google, GMail, an app for the Daily Mail news, YouTube, etc., they don't show up. I find numerous "third-party" apps that are associated with the but the "original" app is nowhere to be found. Am I doing something wrong in my search or do I have a feature turned off that I need.

I'm on the most up to date OS.