when selecting to use a radio group or checkbox group, you need to click the edit button to add items to the group. Initially the group is empty, Click the edit button to populate the group.
to change the label placement, you will need to customize the css.
From the initial Form builder screen, click the Customize CSS Button.
In the Edit CSS Window, change the initial select list to "Form Elements", from the secondary select list, select each, Radio Group, Checkbox Group, Radio Button and Checkbox and change the label placement option to "Right"
