In order to connect the devices you need a circuit board, e.g. this circuit board{Qty:some}.
Further you need many jumper wires jumper wires{Qty:many} to set up connections accordingly to the following circuit drawing. You need male, female and ordinary wires.
To clean up the pathing of cables you can use cable ties like, e.g. these cable ties{Qty:many} and fixate with that the cables at the aluminium strut profile.
You can use a large breadboard to keep a structure between the Arduino Uno{Qty:1}, capacitive sensor MPR121{Qty:1}, Active Buzzer{Qty:1} and H bridge L293D{Qty:1}.


Orange cable – Feedback Potentiometer negative reference rail
Purple cable – Feedback Potentiometer wiper
Red cable – Motor V+ (6V or 12V)
Black cable – Motor V- (Ground)
Yellow cable – Feedback Potentiometer positive reference rail
We used an DIY approach to connect a 12V power supply. It is shown in the picture below:

The black ending was removed from another electronic device with a 12V power supply. By this we can connect the power supply with the circuit board via cable.
The left and right sensor in the circuit diagram is meant to be a electrically conductive wire which is attached to each needle.
The buzzer and LED in the wiring configuration are components of the first use case and may not be required for your set up. Because the provided code is also from the first use case, both components still get mentioned here.