Only certain types of users will see the option to create groups. Once you create groups they will be available wherever you login.
When you first sign up as a teacher you will go the option to create a group.
Or, if you already have an account, you can create a group by scrolling to the bottom of the 'players & groups' tab and selecting 'add group'.
You will then be asked to add a name to the group
After this you can add players
Create multiple players at once
This will allow you to upload a list of players and bulk create them all at once.
Add existing players
This will allow you to select any of the players you have that aren't already in a group and add them.
Create players one by one
You can quickly add players one by one here
You will then be taken to the share screen - here you can download parent letters or password cards. You must click 'complete group set up' to finish making your group.