When students very first start in Google Classroom the workflow to help them with is to navigate to Google Classroom. Find the assignment in the Stream. Click on OPEN. When documents are attached as "Make a copy for each student" the student can not see the attachment in the stream and there is no indicator of an attachment in the stream. Get students in the habit of clicking on OPEN to view the full set of directions, attached resources and any template documents that were provided for them. Students need to click on the document title to open it and edit it. Students then close the document, no save is required if it is a Google Doc, and then choose "TURN IN" or "MARK AS DONE" right in Google Classroom. Students then click on the arrow in the upper left to return to the Stream.
Link to the Graphic: https://goo.gl/DBNRQE