Of course you can. In MapForge, export the map at the desired resolution. 200 dpi or greater is recommended for printing out. That resolution isn't possible for someone using the free demo; a MapForge license is required in order to unlock high-resolution output.
While most users will presumably print on paper, keep in mind that there are other options, too, such as printing maps onto a vinyl mat, or onto cloth. This would require sending the map file to a print shop, though, and can be somewhat costly.