How do you properly simulate lift?

Hello, I am trying to make a flight simulator in unity, but I can't figure out how to simulate the lift correctly. I would have followed a tutorial, but none of the tutorials I can find are realistic. Here is my code so far:

 using UnityEngine;
 
 public class Lift : MonoBehaviour {
 
     //References
     public Rigidbody rb;
     //Variables
     public Vector3 vel;
     public Vector3 liftOffset;
     public float liftoffset = 200f;
     public float speed;
 
     void Start () {
         rb = GetComponent<Rigidbody>();
     }
     
     // Update is called once per frame
     void Update () {
         vel = rb.velocity;
         speed = vel.magnitude;
 
         rb.AddRelativeForce(transform.up * liftoffset * speed * Time.deltaTime);
         
     }
 }

Thanks in advance