Pages free version/can't change layout direction. See screenshot upload, self explanatory.

1. There is no paid version of Pages. Pages is entirely free. All options are available always because there is only one version of the App.
2. To enable the "Layout Direction" options, you need to set the "Pages per Sheet" option above it to something other than 1 page per sheet. Otherwise, the layout direction has no meaning. It refers to the Layout of the pages being printed in the same sheet, not the content within the pages.

The option you highlight has nothing to do with Pages at all (and all Pages versions are 'free').

What you're looking at is the standard print options available in every application.

The layout direction only makes sense when you're printing multiple pages to a single sheet of paper (the printer scales each page down to fit). If you're printing, say, 4 pages per sheet you can choose:

1 2
3 4

or

2  1
4  3

or

1 3
2 4

or:

3  1
4  2

but if you're only printing a single page per sheet, the options make no sense and are therefore disabled.

That's handled by Pages -> Inspector -> Document