Firstly, we use HC-05 Bluetooth Module. Connect the GND and +5V pins of Module to respective pins of Arduino UNO. Then connect the Tx Pin of Module to Rx pin of Arduino. This is because Tx means Transmit and Rx mean Receive.The data transmitted by the Module will be received by the Arduino and vice-versa. Connect the Rx Pin of Module to Tx Pin of Arduino.
Now connection of motors. Connect the L239D Motor Driver Module to the motor and Arduino as shown. Connect the input side of Motor Driver to PWM pins 6, 9, 10, 11 of Arduino. Connect 12v battery or two 9v battery in series as input to the motor. Connect the Left Motor pin and Right Motor pins to motors of chassis.