How to use particle system,PARTICLE SYSTEM

I am fairly new to unity coding, and I am having trouble making my particle system play as soon as the game plays. i have made a few different codes, but I can’t show them since I deleted them. please tell me how to use 2-d particle system at the start of game?
,

public GameObject FireworksAll;
void OnCollisionEnter (Collision coll) {
if (coll.collider.CompareTag (“Player”)) {
Explode ();
}
}
void Explode () {
GameObject firework = Instantiate(FireworksAll, position, Quaternion.identity);
firework.GetComponent().Play();
}