in Libre Office Draw, how do I reorder the pages of a pdf file?
In the view panel you can drag and dop the pages.
You can use click+Shift+click to select followed pages.
And Ctrl+click to select those what you like.
Another way, which does not change the original file, is to use the selection pages during an export:
Export As PDF(create another document)
Pages:Specify page order (e.g. 14;3-6;8;10;12) respecting the syntax given here.