I see that the WillPrint event is triggered after the user dismisses the Print dialog box. I have a PDF where I want to only allow them to print page 1. Can I use the WillPrint event and change the print settings so only the first page is printed? Thank you very much.
No, that's not possible.
As try67 says, the event doesn't work like that.
What you can do, though, is create your own Print button in the file, and
have it set to only print the 1 page you want to print.
However, the user will still be able to change the print settings or use
the built-in Print command and print other pages as well.