Your forms have been given to you based on your Food Control Plan. You can't delete forms, but you can turn them off.
Log in to Admin Console
Go to Forms
Click the Form to open the form editor
Open the "Form Settings" tab
Change the Form Schedule to None.
Turn the Form Library switch off, so the Toggle is Grey
SAVE
The form will then disappear from the form list, and will not be accessible from the mobile app.
Filter to Show Unused/Hidden Forms
You can filter your forms page to show or hide your unused forms, that way once they are turned off you hide them from your view completely.
Log into the Admin Console
Navigate to Forms
Click the More Filters filter
Select Show Unlisted forms
Apply filter
Click the Form to open the form editor
Open the "Form Settings" tab
Set your Schedule for this form