How to make my snowball model to actually shoot like a projectile?

Well i dont know how to script, but i just need it as fastest as possible, a script that can make a model actually shoot, i already have my shootings script. That kinda does damage by online clicking left mouse button.

using UnityEngine; using System.Collections;

public class MeleeSystem : MonoBehaviour {

 public int minDamage = 40;
 public int maxDamage = 49;
 public float weaponRange = 20f;

 public Camera MainCamera;

 private TreeHealth treeHealth;
 private BasicAI basicAi;

 private void Update()
 {
     Ray ray = MainCamera.ScreenPointToRay(new Vector2(Screen.width / 2, Screen.height / 2));
     RaycastHit hitInfo;

     Debug.DrawRay(ray.origin, ray.direction * weaponRange, Color.green);

     if (Input.GetKeyDown(KeyCode.Mouse0))
     {
         if (Physics.Raycast(ray, out hitInfo, weaponRange))
         {
             if (hitInfo.collider.tag == "playerHealth") // If we hit the tag "Tree"
             {
                 treeHealth = hitInfo.collider.GetComponentInParent<TreeHealth>();
                 AttackTree();
             }

             else if (hitInfo.collider.tag == "Enemy") // If we hit the tag "Enemy"
             {
                 basicAi = hitInfo.collider.GetComponent<BasicAI>(); // Find the BasicAi script from the enemy
                 AttackEnemy();
             }
         }

     }
 }

 private void AttackTree()
 {
     Debug.Log("Hit Enemy");

     int damage = Random.Range(minDamage, maxDamage);
     treeHealth.health -= damage;
 }

 private void AttackEnemy()
 {
     int damage = Random.Range(minDamage, maxDamage);
     basicAi.TakeDamage(damage);
 }

}