I want to change the single page setup for 28 pages to a two-page spread format. When I go to "Document Setup" or to "Document Preset" from the masters page it does not give me a two-page master spread, but it does change my layout, and it doesn't hold my inside specs for the spread (ie, the right hand page has the inside specs, but the left hand page does not, it has the spec on the left side the the inside margin.
Moved to the InDesign forum. They will be able to help you here.
Try selecting the master page and right clicking, then select Master Page Options. You should be able to change the number of pages there to 2. You may also need to go back to Layout > Margins and Columns to reset the margins on the master page.