how to wait time after something unity code example

Example 1: wait time in unity

using System.Collections;

private void Start()
{
	StartCoroutine(Wait());
}

IEnumerator Wait()
{
	//To wait, type this:
  
  	//Stuff before waiting
	yield return new WaitForSeconds(/*number of seconds*/);
  	//Stuff after waiting.
}

Example 2: unity wait for seconds

void start() => StartCoroutine(MyIEnumerator());

IEnumerator MyIEnumerator()
{
	Debug.Log("Hello world!");
    yield return new WaitForSeconds(3);
    Debug.Log("Goodbye world!");
}