Prefab + Simple Spawn

A Prefab is a pre-made blueprint for a game object that can be used repeatedly to create instances of that object with the same properties and behaviors. We could for example create a prefab of our random walker with the green material and the RandomWalker script attached.

Please first create a Folder called "Prefabs" if you don't have such a folder in Assets.

We create a prefab, by dragging a GameObject from the Hierarchy to the Assets window, ideally into the folder called "Prefabs"

Create an Empty GameObject with Ctrl+Shift+N   or   GameObject (top bar) -> Create Empty

Name it "SpawnLocation"

Set its Transform component to 0,0,15 in the Inspector (the position of the Camera at 0 , 0 , 0)

In the Inspector click "Add Component", type SimpleSpawn and press the enter key to create a new Script with the name "SimpleSpawn"

Copy the following code into the script:

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

public class SimpleSpawn : MonoBehaviour
{
    // Start is called before the first frame update
    public GameObject prefab;
    public float spawnInterval = 1.0f;

    void Start()
    {
        InvokeRepeating("spawnObject", spawnInterval, spawnInterval);        
    }

    void spawnObject()
    {
    Instantiate(prefab, transform.position, transform.rotation);
    }
}

In the Inspector under the "Simple Spawn" Script component assign under Prefab our RandomWalker Prefab.