What design patterns should I use?

For my task, you need to use design patterns. The task is this: you need to write a GUI application that can import a XML file in which employee data is stored. XML-file has several departments in which employees are located. The employees themselves have their data on the full name, etc. Also necessary that the application can view, edit, add and delete records about employees and departments.

Tell me which in this case it is necessary to choose and use design patterns?

I have never used design patterns before. But having studied them, I suppose that the composite pattern should definitely be used (but its one is not enough 100%).

P.S. To solve the task, I chose the tinyXML2 and Qt library.