I want void loop to go through once

Projects General Guidance
4 
#define RPWM 3
#define LPWM 6
#define REN 4
#define LEN 7

const int buttonPin = 12;

int out1;
int out2;

void setup() {
  pinMode(buttonPin, INPUT);

  pinMode(RPWM, OUTPUT);
  pinMode(LPWM, OUTPUT);
  pinMode(LEN, OUTPUT);
  pinMode(REN, OUTPUT);
  digitalWrite(REN, HIGH);
  digitalWrite(LEN, HIGH);

}


void loop() {



  while (digitalRead(12) == HIGH)
  {
    delay(500);
    digitalWrite(LEN, HIGH);
    digitalWrite(LPWM, HIGH);
    delay(4000);
    digitalWrite(LEN, LOW);
    digitalWrite(LPWM, LOW);
    delay(500);
    digitalWrite(13, HIGH);

    break;

  }

  if (digitalRead(12) == LOW) {
    return;

  }
}