If anyone wants a quick thing to try in the simulator, here's a simple LED blink example with Serial output:

void setup() { pinMode(13, OUTPUT); Serial.begin(9600); }

void loop() { digitalWrite(13, HIGH); Serial.println("LED ON"); delay(500);

  digitalWrite(13, LOW);
  Serial.println("LED OFF");
  delay(500);

In Velxio you can connect an LED to pin 13 and watch it blink, while the Serial Monitor prints the messages in the terminal.