To create users and groups for your Webspace, go to your Webspace's settings (top right).
For Groups:
Click on the Webspace for which you want to create groups
Click on 'Add User Group(s)'
Then click on 'Create a New Group'
Here you will see the screen where you can enter and add the name of your group.
To add users to the group, click on the group, then click show group members.
Then click on 'add users'
Please feel free to reach out if you need extra help; we would be happy to assist you.