how to add number to footer of completed Writer 4.4.3.2 document

Nothing about numbering in LibreOffice seems to make sense. I have two needs. 1) To number a simple 3 page document, putting a number in the footer area without taking space away from an existing document and extending it
to be a 4 page document. Attempt results in space taken from above the footer, messing up the document.

2 I need to number in the footer of an existing 27 page document and stop without putting numbers in the addendums that follow it without expanding the texts and messing up the numbering of the table of contents already done. Also, the
first few pages need Roman numerals that then change to Arabic numbers.