First navigate to: Google Drive
Visually check the list of folders for the one that you think what you're creating should go in and double-click the folder, or use the 'Search in Drive' toolbar at the top to search for a term that would best describe the document. This may elicit a result which will best direct you to where the document should be saved.
Click + New in the top left corner
Choose from the drop down menu the type of document required: Google Docs will open a new document, Google Sheets will open a spreadsheet and so on.
This will create a pop-up asking 'Create in shared folder?' Click 'Create And Share'