Do not use Command Prompt (CMD) for this. You must use PowerShell as an Administrator.
: Select the app you want and click the Get or Install button. If the app requires a purchase, you will see a price instead . How To Download Microsoft Store App Windows 10 UPD
If none of the above methods work, you may need to consider reinstalling Windows 10. This should be your last resort, as it will erase all your files and settings. Before proceeding, make sure to: Do not use Command Prompt (CMD) for this
The Store app updates automatically via Windows Update. To get the latest version (UPD), you need the latest OS build. How To Download Microsoft Store App Windows 10 UPD
Windows 10 comes with a built-in troubleshooter that can help resolve issues with the Microsoft Store app. Here's how to use it: