or and else functions error

So I am trying to write a program using or function. It works al fine till the last or function when i get this error: expected primary-expression before ‘or’ token. And i dont know what am i supposed to do.

And I am not sure even if the else function at the end will be working fine.

#include <LiquidCrystal.h>
int fan = 7;              //dolčimo izhodni pin za ventilator
int redled=8;             //določimo pin rdeče led diode
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);      //Določimo na katerih pinih je priključen LCD
#define pwm 9 ;
int sensor = A0;

void setup()

{                                   //določimo na keteri pini so vhodni in kateri izhodni
  pinMode(fan,OUTPUT);
  pinMode(redled, OUTPUT);
lcd.begin(16, 2);
  lcd.print("HELLO!");
  lcd.setCursor(0,2);
  lcd.print("Tadej Ahac 5.f");
  delay(10000);
  lcd.clear();
  Serial.begin(9600);
}




void loop()
{

if
(pulseIn(sensor,LOW, 80000));
{
analogWrite(fan, 24.5);
lcd.setCursor(0,1);
lcd.print("FAN 10%");
digitalWrite(redled, LOW);
}
or
(pulseIn(sensor,LOW, 80000))
{
analogWrite(fan, 51);
lcd.setCursor(0,1);
lcd.print("FAN 20%");
digitalWrite(redled, LOW);
}
or
(pulseIn(sensor,LOW, 70000))
{
analogWrite(fan, 76.5);
lcd.setCursor(0,1);
lcd.print("FAN 30%");
digitalWrite(redled, LOW);
}
or
(pulseIn(sensor,LOW, 60000))
{
analogWrite(fan, 102);
lcd.setCursor(0,1);
lcd.print("FAN 40%");
digitalWrite(redled, LOW);
}
or
(pulseIn(sensor,LOW, 50000))
{
analogWrite(fan, 127);
lcd.setCursor(0,1);
lcd.print("FAN 50%");
digitalWrite(redled, LOW);
}
or
(pulseIn(sensor,LOW, 40000))
{
analogWrite(fan, 153);
lcd.setCursor(0,1);
lcd.print("FAN 60%");
digitalWrite(redled, LOW);
}
or
(pulseIn(sensor,LOW, 30000))
{
analogWrite(fan, 178);
lcd.setCursor(0,1);
lcd.print("FAN 70%");
digitalWrite(redled, LOW);
}
or
(pulseIn(sensor,LOW,20000))
{
analogWrite(fan, 204);
lcd.setCursor(0,1);
lcd.print("FAN 80%");
digitalWrite(redled, LOW);
}
or
(pulseIn(sensor,LOW, 10000))
{
analogWrite(fan, 255);
lcd.setCursor(0,1);
lcd.print("FAN 90%");
lcd.setCursor(0,2);
lcd.print("HIGH CONCENTRATION");
digitalWrite(redled, HIGH);
}
else
{
analogWrite(fan, 0);
lcd.setCursor(0,1);
lcd.print("HIGH CONCENTRATION");
digitalWrite(redled, LOW);
}
}

There is no or statement in C or C++. You are making your own command up and expect it to work?

There is a logical operation called OR, symbol || and bitwise OR, symbol |. The AND operations use & instead.
You can look them up here,
https://www.arduino.cc/en/Reference/HomePage

Ok I could than probably try using function if else. But the problem is that I am trying to put all of the statments in one if function, so that at the end I can use eles function, if none of the statemnts is true he can do something else.

You need to correct the syntax of your tests but there are other problems such as

if
(pulseIn(sensor,LOW, 80000));

The only command that will be executed conditionally if the pulseIn() returns true is the semicolon at the end of the line. The subsequent code block in curly brackets will always be executed. I assume that is not what you want.

A quick look and I think replace 'or' with 'else if' will do the trick, and leave the single 'else' as it is.

#define pwm 9 ;

It's a good thing you don't use "pwm" ( except maybe if you used it like this "x = pwm;")

Google "C++ tutorial". Choose any of the many, many free tutorials online. Do the first few lessons, up to where the tutorial starts talking about classes.