Here is how to share files with your teachers:
(Note: Make sure wifi is on and you've asked your teacher for permission)
1) Click the finder on the doc
2) Locate your file
3) Open a second window in the Finder (click File> New Finder Window)
4. Click AirDrop
5. Ask your teacher to open Airdrop (Finder doc icon>Airdrop) on his/her computer and ask for your teacher's computer name/number.
When your teacher's computer appears in your AirDrop window, drag your file onto your teacher's computer.
6. Click Send.