Page numbering in Pages

Provided it is a word processing document, and not page layout, each new section has a Document : Section panel on which you choose to [ ] Match previous section to disable the page numbering format for the previous section. With the page number inserted in the header or footer, you then choose the Page numbering format.

I just created a four-section Pages v13.2 word processing document where the page numbering is different on each section:

1. None (no page number inserted)
2. Integer 2 (page number inserted)
3. Roman Numeral iii (page number inserted)
4. Roman Numeral A (set start at 1 to change from D to A)

If I can do this, so can you.

You will need to establish a separate section for each of the 1-4 parts of the book. Each section can have its own page numbering format that you establish from the Document panel : Section tab. On that panel, for each section, you deselect Match previous section.

If you need an index, then Pages is the wrong tool and MS Word, or any other third-party word processing application that can generate an index would be advised. MS Word, LibreOffice, Mellel, are all capable of producing an index. Pages has never had an index generation feature, or a body text sorting capability to form an alphabetical glossary, and Apple does not update past versions of Pages with any new features.