How can the title name be turned off on the top of every single page in PDF export, please?
Assuming you mean ‘when I compile a project to PDF’, then you do that in the Compilation Dialogue. Make sure you’re in All Options, then there’s an option down the left hand side (Layout, I think) which allows you to specify page headers / footers etc.
On the other hand, if you’re simply printing a number of documents out from the Binder to get to the standard Mac Print dialogue, then you can change the headers in the File > Page Setup > Scrivener dialogue.
HTH.