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.
Move existing players
This will allow you to select any of the players you have that aren't already in a group and move them to the newly created group
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.