I'm afraid I'm going to get marked down since I don't comprehend what you're asking...
The only way to adjust the visibility of the Legend is to use the ribbon.
If you're printing a sheet, you'll want to use File > Page setup, but if you're using a dashboard, you'll want to use real placement.
When people talk about printing to PDF, it makes me nervous. You've sacrificed much too much utility. However, I would love to create a dashboard to precisely regulate legend position.
Know more about Stacked bar and line chart -Tableau