Couldn't execute bluetooth command simultaneously

Hi all, I'm very new to arduino and currently doing a project on a RC car. The car works pretty fine but just one last thing that frustrates me which is the outputs (eg. when rear light left blinking signal is ON, I couldn't turn on the front lights). I always need to wait until the blinking rear light signal code is completely ended before I can start giving a new command..

Below is the coding I have done.. anyone can help?

char t;

int SPEED1 = 80;      // Steering Speed
int SPEED2 = 200;      // Engine Speed

void setup() {
pinMode(13,OUTPUT);   // Motor A forward
pinMode(12,OUTPUT);   // Motor A reverse
pinMode(11,OUTPUT);   // Motor B forward
pinMode(8,OUTPUT);    // Motor B reverse
pinMode(9,OUTPUT);    // Front LEDs (x2)
pinMode(5,OUTPUT);    // Left rear LEDS (x2)
pinMode(3,OUTPUT);    // Right rear LEDS (x2)
pinMode(10,OUTPUT);   // Voltage of Steering
pinMode(6,OUTPUT);    // Voltage of Engine

Serial.begin(9600);

}

void loop() {
if(Serial.available()){
 t = Serial.read();
 Serial.println(t);
}

if(t == 'F'){            //Forward
 digitalWrite(8,HIGH);
 analogWrite(6,SPEED2);
}

else if(t == 'B'){      //Backward
 digitalWrite(11,HIGH);
 analogWrite(6,SPEED2);
}

else if(t == 'L'){      //Left
 analogWrite(10,SPEED1);
 digitalWrite(12,HIGH);
}

else if(t == 'R'){      //Right
 analogWrite(10,SPEED1);
 digitalWrite(13,HIGH);
}

else if(t == 'W'){      //Frontlights ON with 30 magnitude
 analogWrite(9,30);
}

else if(t == 'w'){      //Frontlights OFF
 analogWrite(9,0);
}

else if(t == 'V'){      //Rearlights ON with 30 magnitude
 analogWrite(5,30);
 analogWrite(3,30);
}

else if(t == 'v'){      //Rearlights OFF
 analogWrite(5,0);
 analogWrite(3,0);
}

else if(t == 'A'){      //Left Blinking Signal
 analogWrite(5,0);
 delay(500);
 analogWrite(5,30);
 delay(500);
 analogWrite(5,0);
 delay(500);
 analogWrite(5,30);
 delay(500);
 analogWrite(5,0);
}

else if(t == 'Q'){      //Right Blinking Signal
 analogWrite(3,0);
 delay(500);
 analogWrite(3,30);
 delay(500);
 analogWrite(3,0);
 delay(500);
 analogWrite(3,30);
 delay(500);
 analogWrite(3,0);

}
 
else if(t == 'S'){      //STOP (all motors stop)
 digitalWrite(13,LOW);
 digitalWrite(12,LOW);
 digitalWrite(11,LOW);
 digitalWrite(8,LOW);
}

First of all, please edit your post and put the code inside code tags.

How to do two things at the same time