New Revit file, what API method

Instead of using the current Revit file, I would like to create a new Revit File from a Revit template
than starting to populate with elements.
So far the only instructions I found in this forum are referring to an Orchid package that I did not succed to install. Do you have any suggestions about the API (revit 2019) method to use?

I could not find such method. I am also interested in this. I thought the RevitServices library might have sth but I could not find anything but calling the current Revit document.

Anyway, you might use Clockwork node to save the current Revitfile as and then create your new elements in the new file. You can either keep the old elements or select them and delete them automatically (Springs has a node that helps deleting elements). You can put the file name as an input. Not the cleanest and fanciest way but it practically works.