I’ll bite once, to answer your specific question.
In Google Documents with a browser, open the document you wish to move into Scrivener. Menu → File → Download. Pick one format as (see @kewms suggestions). File will go to your ~\Downloads folder (by default). Open Scrivener project where you want to import the document. Menu: File->Import and pick that downloaded file.
There are other ways to get text from one to another app. That’s a standard feature of what Windows brought to the party starting in the 1980’s. Explore.
For more information and guidance for Scrivener importing, read Section 9.1 “File Import” of the Scrivener User Manual".