Sizing when printing a booklet

I am trying to print a card from a PDF file downloaded from Canva. 

I have printed in "Booklet" style before and it's worked great. This time, when I go to print the card in booklet style, the file has a large margin around the edges. I want to zoom in the size of the PDF on the booklet, but I can't find that as an option anywhere. If I go to page setup, there is a section for margins, but it doesn't allow me to change anything. 

Does this make sense? How can I resize the PDF when printing as a booklet?