In this circuit, the proximity sensor acts as a switch for LED bulb. Here, if an object is less than 10cm distance from the sensor, the LED will glow, else it will turn off.
Circuit diagram
(credits: https://www.circuito.io/)

Here, you can connect resistor and LED to board directly without breadboard. If you do not have LED, replace 5 with 13 in the code below which will make the on-board LED blink.
Code
const int trigPin = 3;
const int echoPin = 2;
void setup() {
pinMode(5, OUTPUT);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
Serial.begin(9600);
}
void loop() {
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
long duration = pulseIn(echoPin, HIGH);
float distance = duration * 0.034 / 2;
float bright = 306 - (distance* 10.2 );
if (distance<10){
digitalWrite(5,HIGH);
}
else digitalWrite(5,LOW);
Serial.print("Distance: ");
Serial.print(distance);
Serial.println(" cm");
delay(100);
}