Please use the correct template to create a C++/winrt project. If similar errors occur, it is recommended to restart the visual studio or reinstall C++ (v14x) Universal Windows Platform tools or nuget package Microsoft.Windows.CppWinRT.

https://learn.microsoft.com/en-us/windows/uwp/cpp-and-winrt-apis/intro-to-using-cpp-with-winrt#visual-studio-support-for-cwinrt-xaml-the-vsix-extension-and-the-nuget-package