Hello Gail. Section 24.19.1 of the Scrivener manual explains the numbering options for footnotes. Depending on how your Binder is structured, you might need to change the numbering settings in the “Footnotes & Comments” options when customizing to have the numbering reset by section. (You can access a PDF of the manual via Scrivener’s Help menu.)
If you’re not familiar with how to customize your compile settings, we have a 4-part video series titled “Getting Your Work Out” on the Mac tutorial videos page. Those videos demonstrate using the built-in compile formats as well as show the customization process. Seeing them might be helpful.