To print a score, you use the menu: [File|Print], use a windows shortcut <ctrl-P> or the print button on the buttonbar . The usual windows print-screen will guide you further through the printer and page selection.
To print a single part from a score you may deselect the 'score' box in the score dialog and select the desired part.
You can preview pages using the button What you view on screen will be what you are getting on paper.
Printing using a non-licensed installation will require you to enter a sequence of letters and digits correctly.