JavaFx - What is the design patterns for the Pure Java coding ? (No CSS or FXML)

Good evening, everyone!
I'm having trouble to get the knowledge of the design patterns for a JavaFx project made entirely of Java (Pure Java Coding, no CSS or FXML).
Can someone explain to me and give me a simple example of it ?

EXTRA : Also , what is the difference of the the Property objects properties (ex. StringProperty) to the normal ones (ex. String)?
Sorry for the newbie questions and thank you in advance!