Is there a way to create a MASTER in Calc so I don't have to format each page separately?

do I have to format each page separately?

Define a customized Page Style in Styles Manager (F11 or View -> Styles; second icon beneath word Styles; hover over the icon will show tool tip Page Style) and assign that to each sheet - and if you want that Page Style to appear on all your new Calc documents as well, define a new default template having this page style definition.

Pages are (next to) only relevant for printing in Calc, and there’s no way to format each page separately.

The page formattting (Page Style) defining margins, primitive headers and footers, rows or/and columns needing to be repeated, is by default common for all the sheets, but you can define dedicated Page Styles, and assign to each sheet any of the Page Styles availabel from the Styles panel (F11).

If you actually are asking for a “master” concerning details of the formatting of a sheet (column widths e.g.), and how to apply it, please do so explicitly. (“Page” isn’t the appropriate term then.)