Two page view in Preview workaround
I wanted to read a two page pdf of some sheet music side by side.
But when you select View > Two Page, it didn't appear to work,
only page one displayed.
The reason is Two Page defaults like a book to even pages left, odd pages right.
The first page is odd, so it displays as a single page with no zero even page.
Ok, before you hurt your brain trying to make sense of this,
The workaround is to insert a filler first page, making your page one into page two.
I just option drag a page to the top of the thumbnail section, creating a new page.
Now the two page display operates as you might expect.
Mac mini, macOS 12.7