arduino uno parking system project loop run automatically - while-loop

Question

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Servo.h>
LiquidCrystal_I2C lcd(0x3F, 16, 2);
Servo servo1;
Servo servo2;
int IR_ENTER = 3;
int IR_EXIT = 4;
int IR1 = 5;
int IR2 = 7;
int IR3 = 8;
int IR4 = 9;
int welcome = 90;
int goodbye = 90;
int pos = 0;
int carParked = 0;
int parkingLot = 5;
void setup()
{
lcd.init();
lcd.backlight();
servo1.attach(12);
servo2.attach(13);
pinMode(IR_ENTER, INPUT);
pinMode(IR_EXIT, INPUT);
pinMode(IR1, INPUT);
pinMode(IR2, INPUT);
pinMode(IR3, INPUT);
pinMode(IR4, INPUT);
}
void loop()
{
lcd.setCursor(0, 0);
lcd.print("Automatic Car");
lcd.setCursor(0, 1);
lcd.print(" Parking System");
delay(500);
if (digitalRead(IR_ENTER) == LOW)
{
servo1.write(welcome);
lcd.clear();
lcd.setCursor(0, 0);
lcd.print(" WELCOME!");
lcd.setCursor(0, 1);
lcd.print(" PLEASE ENTER");
delay(1000);
servo1.write(0);
}
if (digitalRead(IR_EXIT) == LOW)
{
servo2.write(goodbye);
lcd.clear();
lcd.setCursor(0, 0);
lcd.print(" GOODBYE!");
lcd.setCursor(0, 1);
lcd.print(" SAFE JOURNEY");
delay(1000);
servo2.write(0);
}
while (parkingLot >= 1)
{
if (digitalRead(IR1) == LOW || digitalRead(IR2) == LOW || digitalRead(IR3) == LOW || digitalRead(IR4) == LOW)
{
carParked = carParked + 1;
parkingLot = parkingLot - 1;
lcd.clear();
lcd.setCursor(0, 0);
lcd.print("Parking Lot");
lcd.setCursor(0, 1);
lcd.print("Left : ");
lcd.print(parkingLot);
delay(2000);
}
}
if (parkingLot == 0)
{
lcd.setCursor (0,0);
lcd.print(" SORRY :( ");
lcd.setCursor (0,1);
lcd.print(" Parking Full ");
delay (3000);
lcd.clear();
}
}
Hi im beginner in arduino, I want to create this car parking system project. I have problem with the while loop for the code, when I compile and upload the code to arduino, it started write to lcd the parking slot left automatically until 0 and show parking full, but actually it should be running once the ir sensor at the parking triggered.
like when the car entered the parking slot which is empty, the sensor will detect the car and write on the lcd, parking slot left : 3
I have 4 slot of parking which have ir sensor for each parking`