Построение последователя строки и продолжайте получать ошибки просто нужна помощь в правильном направлении, чтобы закончить ошибку кода, расположенную внизу

const int leftMotorPin = 9;
const int leftSensorPin = A0;
const int rightMotorPin = 8;
const int rightSensorPin = A1;
int rightlightThreshold = 100;
int lightThreshold = 300;
int buttonPin = 7;
int buttonState = 0;
int resistorValue1 = 0;
int resistorValue2 = 0;
int thresHoldAverage;



void setup()
{
//Set Baud Rate, Required to use Serial Monitor
Serial.begin(9600);
pinMode(leftMotorPin , OUTPUT);
pinMode(leftSensorPin, INPUT);
pinMode(rightMotorPin , OUTPUT);
pinMode(rightSensorPin, INPUT);
pinMode(buttonPin, OUTPUT);




  
  }
  
  


void loop()

{
  int main(void)
  {


//Read Sensor Valuesif (buttonState == HIGH)
String int buttonState = digitalRead(buttonPin);
   
   while(buttonState == LOW)
  {


   int reading1 = analogRead(A0);
   int reading2 = analogRead(A1);
   int resistorValue1 = (reading1 + reading2) / 2;
    return;
   delay(10000);
   }
   buttonState = digitalRead(buttonPin);
    while (buttonState == LOW)
    {
     
   int reading1 = analogRead(A0);
   int reading2 = analogRead(A1);
   int resistorValue2 = (reading1 + reading2) / 2;
   delay(10000);
   return;
   int thresHoldAverage = (resistorValue1 + resistorValue2 / 2);
    }
}
   
//int rightLightLevel = analogRead(rightSensorPin);
// If right light sensor is greater than threshold
// then turn right Motor on, else turn right Motor off

String int buttonState = digitalRead(buttonPin);
while (buttonState == HIGH)
 {
    int thresHoldAverage;
    digitalRead (A1);
    digitalRead(A0);
    }
if ( rightlightThreshold > thresHoldAverage) 
{
  //( rightlightThreshold > thresHoldAverage);

digitalWrite( rightMotorPin , HIGH);
}
else
{

digitalWrite( rightMotorPin , LOW);
}
//int leftLightThreshold = analogRead(leftSensorPin);

// If left motor sensor is greater than threshold
// then turn left Motor on, else turn left Motor off

if (lightThreshold > thresHoldAverage)
{
  //(leftLightLevel > thresHoldAverage)

digitalWrite( leftMotorPin , HIGH);
}
else
{
digitalWrite( leftMotorPin , LOW);

}

}
}

Arduino: 1.8.13 (Mac OS X), Board: "Arduino Uno"

/Users/xavier/Documents/Arduino/finalprojectnew/finalprojectnew.ino: In function 'void loop()':
finalprojectnew:38:3: error: a function-definition is not allowed here before '{' token
   {
   ^
finalprojectnew:71:12: error: two or more data types in declaration of 'buttonState'
 String int buttonState = digitalRead(buttonPin);
            ^~~~~~~~~~~
/Users/xavier/Documents/Arduino/finalprojectnew/finalprojectnew.ino: At global scope:
finalprojectnew:107:1: error: expected declaration before '}' token
 }
 ^
exit status 1
a function-definition is not allowed here before '{' token


Arduino: 1.8.13 (Mac OS X), Board: "Arduino Uno"

/Users/xavier/Documents/Arduino/finalprojectnew/finalprojectnew.ino: In function 'void loop()':
finalprojectnew:38:3: error: a function-definition is not allowed here before '{' token
   {
   ^
finalprojectnew:71:12: error: two or more data types in declaration of 'buttonState'
 String int buttonState = digitalRead(buttonPin);
            ^~~~~~~~~~~
/Users/xavier/Documents/Arduino/finalprojectnew/finalprojectnew.ino: At global scope:
finalprojectnew:107:1: error: expected declaration before '}' token
 }
 ^ERROR
exit status 1
a function-definition is not allowed here before '{' token