It's actually not in the app store, and it may only be available on Pixel phones. You get the app not by downloading it from anywhere, you just enable "developer mode" in the system settings, and the app magically appears in your app menu (the full menu, not on any home screen by default). There is a subreddit dedicated to this app ( https://www.reddit.com/r/androidterminal/ ).

I've never used a Samsung phone, but I think their DeX environment might allow you to do the same things that the "terminal" app supplies.

If you can't get either of the above to work, give Termux a try. It's not full gnu/Linux, but it's pretty close.