Please do email the group with your questions. Remember if you don’t know the answer then others probably don’t as well.
If you want to share a document with your course-mates you can do that by entering the email email@example.com
Documents that are shared with you will appear in the shared with me part of your drive. If you want to arrange them in a logical order then you can do that by putting a tick in the box next to a document and clicking on Add to My Drive. You can then file it in your folders. This doesn’t effect who has access to the document or how other people see it. It just helps with your organisation of docs shared with you.