Parking Lot

Hi, I have a problem with my parking lot and I cant fix it, im a new user on Arduino and in programming aswell so I hope that someone could help me please.
My parking lot is composed by 2 Servos ( one servo for the entry of the park and the other one for the out part), 2 IR sensors and 1 LCD 16x2 I2C.
When the cars pass the sensors it will activate the servo that works like a barrier of a irl parking lot and the car will pass, the park has 6 spots. My Problem is that I wanted to make the servo stoped and a message would appear on the LCD that the park is full but I cant do that so I hope that someone could help me.
Sorry for my bad english, tell me anything you need if you dont understand someting :).

Il leave here the program I have so far.

Parque_de_Estacionamento_Automatizado_v5.ino (1.98 KB)

What did you try?

if (contlugares == 0)
{
    lcd.setCursor(....); 
    lcd.print(....);
}

Your code will work, but it would generally be considered bad practice to try maintain two variables with opposite meanings...

   contcar=contcar+1;
    contlugares=contlugares-1;

Too much chance you may forget to adjust one, and then they would be "out of step" with each other.

const int totalSpaces = 6;
int spacesUsed = 0;

//Car in...
spacesUsed++;
//Car out...
spacesUsed--;

//Display spaces remaining
 lcd.print(totalSpaces  - spacesUsed);

//If car park full...
if (spacesUsed == totalSpaces)
{
  ....
}