To add a new form group please go to; Admin > Config > Core Set Up > Forms
At the top of the page, there are 2 boxes where you can input an Abbreviation for the new form group, and the description. Type in the new name and click "Save New Form Group."
Your new form group will then show at the bottom of the list - the box will be greyed out to highlight that there are no children in this group yet:
You also have the option to delete the group if no children have been placed in there yet.
Further guidance on assigning children to a New form for September through Group Updater, can be found Here.