You can insert a page break via Insert | Manual Break and select Page Break. Alternatively you can force a new page with Ctrl+Enter.
Slackware 15 (current) 64 bit
Apache OpenOffice 4.1.16
LibreOffice 26.2.3.2; SlackBuild for 26.2.3 by Eric Hameleers
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I hate this damn computer, I wish that I could sell it.
It won't do what I want it to, Only what I tell it.
Alternately, if the text is continuous from existing text, simply position your cursor where you require the new text to be, and type, or if you have the information in a file, use /Insert /File; OpenOffice will expand the page structure as necessary.