With your Coda account you create docs which are part of a workspace.
Workspaces is a concept you have to get familiar with before getting a teacher license.
Click All docs at the top left of Coda to go to your workspace
Your discount should get activated within a week time
Is my discount active?:
How to work with other people in one Doc
Only add other people as editors to your docs to be able to collaborate, never as Doc Maker.
How to add collaborators to your doc:
At the top right of your Doc you can find a Share Button.
Invite your collaborators here as Editors.
🔼 In this example there are two Doc Makers which the account gets charged for monthly 🔼
Your account should ONLY have one Doc Maker which should be your own account