how to wait a couple seconds before exectuting code in unity code example

Example 1: how to make a line of code wait unity

//In the example below the script will right "Hello" and 3 seconds later write "Goodbye" in the console
Start()
{
  	//Call the function Example()
	StartCoroutine(Example());
}

Example()
{
  	Debug.Log("Hello");
  	//wait 3 seconds
	yield return new WaitForSeconds(3);
  	Debug.Log("Goodbye");
}

Example 2: wait for a second unity

void Start()
    {
        //Start the coroutine we define below named ExampleCoroutine.
        StartCoroutine(ExampleCoroutine());
    }

    IEnumerator ExampleCoroutine()
    {
        //Print the time of when the function is first called.
        Debug.Log("Started Coroutine at timestamp : " + Time.time);

        //yield on a new YieldInstruction that waits for 5 seconds.
        yield return new WaitForSeconds(5);

        //After we have waited 5 seconds print the time again.
        Debug.Log("Finished Coroutine at timestamp : " + Time.time);
    }