Automator to open PDFs on multiple desktops

I'd like to use Automator to open specific pdf file file with Preview app:

some PDF at full screen on specific desktop: e.g. file 1 on desktop 1, file 2 on desktop 2 (full screen)

some PDF files one the same desktop: e.g. n.2 files on the same desktop where each file uses half screen

Once I decided requirement I'd like to open all files in one shot click.

What do you suggest to start about automator ?