button function on unity5

using UnityEngine;
using System.Collections;

public class Player : MonoBehaviour
{
    public Vector2 jumpForce = new Vector2(0, 300);
    public GameObject Egg;
    public Transform eggpoint;
 
    // Use this for initialization

    void Start()
    {

    }


    // Update is called once per frame
    void Update()
    {
        if (Input.GetKeyUp("space") || Input.GetMouseButtonDown(0))
        {
            GetComponent<Rigidbody2D>().velocity = Vector2.zero;
            GetComponent<Rigidbody2D>().AddForce(jumpForce);
        }

            if(Input.GetKeyDown(KeyCode.Return))
            {
                Instantiate(Egg, eggpoint.position, eggpoint.rotation);
            }

    }
}

so as you guys can see in the separate box how i am instantiating my egg droping code.and i am achieving this by pressing the return or enter button on the keyboard ,what i want to ask is how can i use a button to do it rather than the enter .so i have placed a ui button on my game screen but as i am absolute beginner i cant figure out how to connect the button and the function please guide me to the right tutorial.

This is what you need:

You also should watch tutorials on Unity UI: