The joystick module contains an analog 2-axis joystick with 2x 10K ohm pots and push button function (underneath the joystick).
The 5 connector pin descriptions are printed on the PCB.
You will need to connect the Ground Pin to be able to read the digital push-button pin.
You will need to connect the Ground Pin and Vcc Pin to be able to read the analog X and Y values.
A push-on operating knob is included with the module.
Sample Code to test your joystick module: