I created a form to add data to my database and saved them. No unique identifier was created so I cannot edit the fields.

The reason why you do not have values in your UID field is because you did not set that field properly in your CD wizard.

Please change it to hidden field with random text value. To do that, click the "Change” button and you’ll get field type dialog. Select "Hidden field” and "Random text” as shown on the image below:
This way, dbBeeUniqueIdentifier field will get a unique value for every added record, and you’ll be able to edit it using the Admin app.
For the records that are already added and do not have dbBeeUniqueIdentifier value use the command "Populate UID” from your context menu next to admin project that uses same Excel sheet (see the image below):
To read more about context menu please go to http://www.dbbee.com/dashboard-context-menu