Portrait orientation is when the page is taller than it is wide. Landspace orientation is when the page is wider than it is tall.
In Microsoft Office (Word, PowerPoint, Excel, etc.): under Settings in the print menu, click Portrait Orientation and select Landscape Orientation.
In other programs, including web browsers: open the print dialog box by selecting File, then Print or pressing Ctrl+P. Click Preferences or Properties and choose your preferred orientation.