Yes, the "Templates" are there for you to base your fomr design on and are to be edited.
If you go to the "Create New Form" tab and locate the Template you want to create a from from to edit, mouse over the Template thumnail and click "Use Template". This will create a new form from the Template that you can edit.
The changes you make are saved automatically. When you sign back into FormsCentral later your form/s and changes will be there.
Here is a bit of an overview http://forums.adobe.com/docs/DOC-1413
Let me know if you have more specific questions.