Scriptum/Assets/TakingDamage.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class TakingDamage : MonoBehaviour
{

    private bool inRange = false;
    public GameObject other;
    private bool firstAttack = false;

    void OnTriggerEnter2D(Collider2D collision)
    {
        if (collision.tag == "PlayerHitbox")
        {
            inRange = true;
            firstAttack = false;
        }
    }

    void OnTriggerExit2D(Collider2D collision)
    {
        inRange = false;
        timer = 0f;
    }

    private float timer = 0f;
    private float waitTime = 1.0f;

    void Update()
    {
        if (inRange == true)
        {
            if(firstAttack == false)
            {
                if(timer >= 0.15f)
                {
                    firstAttack = true;
                    other.GetComponent<Player>().TakeDamage(1.0f);
                    timer = 0f;
                }
            }
            if (timer >= waitTime)
            {
                timer = 0f;
                other.GetComponent<Player>().TakeDamage(1.0f);
            }
            timer += Time.deltaTime;
        }
    }
}