The editor is used to create and save new programs or to open, modify and save existing stored programs (in Python, stored programs are usually called modules). If you need a new editor window then choose New Window from the File menu.
To run a program select Run Program from the Run menu (or press F5). The results of the program will appear in a special Output window.
The editor is customised for writing Python programs: it will highlight and lay out your code for you in the same way as the interpreter.