I assume you used New From Template Chooser > Page Layout > Flyers > Real Estate Flyer.
I found it to be quite odd. Some are text boxes, some are shapes. Some I could remove by selecting and deleting. Some I could not delete because it removed the text as well. Some I could change to white. Curiouser and curiouser, I had to add a stroke (line) then turn it white!
Inspector > Graphic Tab > Stroke. Change from None to Line. Then click on the colour button (middle button) to get the colour palette and choose white.
Wierd! If you get on top of this, save as a custom template for future use.
Sometimes it is better to start with a blank template and design your own layout. Then you know what you have!