How to parent a gameobject OnTriggerEnter?

Hi, for my game I am attempting to make a car enter/ exit script. I’m really confused on how I would set my player to be a child of the object it is colliding with. This is what I have so far. Thank you so much!

 public class CarSystem : MonoBehaviour {
    	public Transform player;
    	private GameObject car;
    
    	void Start()
    	{
    
    	}
    		void OnTriggerEnter(Collider other) {
    		if (Input.GetKey ("e") && other.gameObject.tag == "Car")
    		{
    			Debug.Log("Entered the car!");
    			//set first person controller to child of car
    			//set first person controller position to 0,0,0
    		}

Parent is a veriable in gameobjects so you would just set it to what ever you want

so say we have the player and you want to parent it to car and for i will randomly choose that the script is on the car

 player.transform.parent = this.gameObject

now the player’s parent is the gameobject that the script is attached to
To un-parent you set the parent to null

player.transform.parent = null;

now the player has no parent

so with your code, you work from the collider of the car i assume so it would become

  void OnTriggerEnter(Collider other) {
             if (Input.GetKey ("e") && other.gameObject.tag == "Car")
             {
                 Debug.Log("Entered the car!");
                 //assuming other is a collider attached to the 
                 //car as it is tagged
                 this.transform.parent = other.transform;
                 //set first person controller to child of car
                 //set first person controller position to 0,0,0
             }