If default print settings don't satisfy your needs, you may:
- export the plan with Plan > Export to SVG menu item and print it with Inkscape
- choose 3D view > Create Photo menu item and create an image with more parameters.

If in page setup, 3D view is disabled, that means that your computer is unable to create offscreen images. The photo creation pane will let you create very nice images with a better quality though, because it doesn't compute images the same way.

If you can't have offscreen images, please read the FAQ , there might be solutions for you.