The first thing I would recommend doing is checking the built-in Help section. If the software doesn't have that section, locate the installation folder and look for Readme files or User Guides in PDF or CHM format. However, I have installed the application and used a template from the available list. I was able to print it, but the software doesn't allow the operation you have mentioned in your question. Try creating 2 labels and then export them to another format (eg. as image) and load Photoshop or Gimp and add them to one page only. Before you do that, apply all the edits to both labels and then export.
