If I understand what you want, you just want to make a new PDF that consists of just one page from a larger, multipage PDF?
Just open the large PDF in the OS X Preview app and in the View manual make sure to checkmark Thumbnails so the PDF thumbnails appear along the left side.
Now scroll down and select the thumbnail of the one page you want and drag it to the desktop. That will make a new PDF file of just that one page.