How can I share a Google document with my professor?

Step-by-step guide

Select the file you want to share.
Click Share or Share .
Under Share with people and groups, enter the email address you want to share with.
To change what people can do to your file, on the right, click the Down arrow Viewer, Commenter, or Editor.
Choose to notify people:
- If you want to notify people that you shared a file with them, check the Notify people box. If you notify people, each email address you enter will be included in the email.
- If you don't want to notify people, uncheck the Notify people box.
Click Share or Send.
For more information view: https://support.google.com/a/users/answer/9305987#3.1