Basic USB - Virtual Com Port

//USBSerial usb;
#define pinLED PC13

void setup() {
  // Serial is used for USB VCP and Serial1,Serial2,Serial3 are for TTL UART
  Serial.begin(115200);
  pinMode(pinLED, OUTPUT);
  Serial.println("START");
}

void loop() {
  digitalWrite(pinLED, HIGH);
  delay(1000);
  digitalWrite(pinLED, LOW);
  delay(1000);
  Serial.println("Hello World!");
}