How to code Arduino used countdown timer (buzzer), 4 pir sensors, and relay? They worked parallel but what I need is work sequentially - arduino-uno

Question

How do you program Arduino to do a countdown timer 10 times using a buzzer, then after that, the light will turn on (relay). In addition, 4 PIR sensors will detect movement, if there is movement, the light will turn off for 10 seconds after which the light will turn on again. I already try to code but something feels off because the light is on at the start and the sensor detects when the timer is still running.
Here is the code that I try to code:
#define relayPin 12
#define pirPin1 8
#define pirPin2 9
#define pirPin3 10
#define pirPin4 11
int val1 = 0,val2 = 0, val3 = 0, val4 = 0 ;
long buzzerFrequency = 1000;
float buzzerDuration = 100;
int startNumber = 9; //countdown starts with this number
int endNumber = 0; //countdown ends with this number
const int buzzerPin = 6;
void setup() {
// put your setup code here, to run once:
pinMode(buzzerPin,OUTPUT);
pinMode(relayPin,OUTPUT);
pinMode(pirPin1, INPUT);
pinMode(pirPin2, INPUT);
pinMode(pirPin3, INPUT);
pinMode(pirPin4, INPUT);
Serial.begin(115200);
}
void buzzer(){
if (startNumber >= endNumber) {
for (int i = 0; i <= 1; i++){
tone(buzzerPin,buzzerFrequency,buzzerDuration);
}
delay(1000);
startNumber--;
}
}
void allPir(){
val1 = digitalRead(pirPin1);
val2 = digitalRead(pirPin2);
val3 = digitalRead(pirPin3);
val4 = digitalRead(pirPin4);
if(val1 == HIGH || val2 == HIGH || val3 == HIGH || val4 == HIGH){
digitalWrite(relayPin, HIGH);
Serial.println("Movement! delay 10 second");
Serial.println("Light off");
delay(10000);
}else{
digitalWrite(relayPin, LOW);
Serial.println("No Movement");
Serial.println("Light on");
}
}
void loop() {
// put your main code here, to run repeatedly:
buzzer();
allPir();
}
The countdown should have finished first with a buzzer sound, then the light will turn on, then the PIR sensor will check the environment. How to fix it? and what do I need to add?