What are the standard default margins set in Scrivener starting with a blank page? Does it differ from using the Novel template? And what is the easiest, quickest way to re-set the margins? Thnx! 
New blank projects are created with 1“ margins by default. These are most easily changed from the Page Settings compile option pane, which will by default track the default print settings, from the standard Mac File/Page Setup… tool. You can either just simply disable that tracking and set things up here, or change them in Page Setup, under the ”Scrivener" settings section.