New guy trying to learn

int led = 0;
int ledPin = 13;
void setup() 
{
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);
  Serial.println("Press 1 to turn LED ON");
  Serial.println("Press 0 to turn LED OFF");
}

void loop() 
{
 if (Serial.available() > 0)
 {
  led = Serial.read();
    if (led == '1')
  {
    digitalWrite(ledPin, HIGH);
    Serial.print("LED ON");
    Serial.println(" ");
    delay(9000);
  }
   else if(led == '0');
  {
    digitalWrite(ledPin, LOW);
    Serial.print("LED OFF");
    Serial.println(" ");
  }
 }
}

You ignored Awol's advice regarding the semicolon.

What did we agree about the semicolon?

I don't know why you do that - what's wrong with

Serial.println("LED OFF");

?

yeah, it was my mistake, I was sure I deleted it and apparently, I didn't after adding the if right by the else. anyways that fixed it so thank you very much!

and for this:

Serial.print("LED OFF");
    Serial.println(" ");

I add the 2nd serial print since it makes it go down a line, making it more intuitive

Escape sequences

Can also use \n etc. in your quoted text.

Serial.print("LED OFF \n");