Double sided printing? Facing Pages? Spreads?

You have a duplicate thread here - I believe
Locking this one
https://community.adobe.com/t5/indesign-discussions/double-sided-printing-facing-pages-spreads/m-p/14679350#M577422

If your pages are NOT gong to be viewed adjacent to each other, your "Spreads" will only be on page wide, so Single Pages is what you want. You can export a PDF normally.
If you plan on having a format that resembles a book / magazine with images or text that flow across multipule pages, use Facing Pages for your document set-up.  If you are printing the document, don't export your document as spreads, ask your print provider what they want.  If you are printing yourself. you'll have to use the "Print Booklet..." feature.  You might need to use the internet to show you how to do this if you don't already know. It's not always a straight forward as it should be.

If it's a single sheet printed both sides, set it up as two separate pages.

If you want to print on both sides your documents have to be set up as document with facing pages, as probsbly you have elements relative to the spine, like page numbers, running headers or margins.

For print export the document as single pages.