There are no margin controls. What you have is a choice of two ways of printing:
1. Exactly as the original - same size and position. If the design is very close to the left side, it will probably be cut off because your printer can't print that close to the edge. But this is a very important mode, especially for things like official forms which must be exact.
2. Scaled to fit. Here, we work with the "printable area", the space your own printer is able to use (different for each printer model). The pages are scaled into that area, so almost never printing life size. Any blank space in the PDF is scaled too.
You choose between these (and other) options in the print dialog.