Handle activating/deactivating objects in a scene on startup

ActivateOnStart.cs

using UnityEngine;

/// <summary>
/// Add this component to an empty game object and assign other game objects
/// to it for activation/deactivation on start.
///  
/// This is useful for ensuring certain game objects are active/inactive before
/// other components' Start() methods are called, as this component has a default
/// execution order of -1000.
/// </summary>
[DefaultExecutionOrder(-1000)]
public class ActivateOnStart : MonoBehaviour
{
    [SerializeField]
    private GameObject[] objectsToActivate;
    [SerializeField]
    private GameObject[] objectsToDeactivate;
    
    private void Start()
    {
        foreach (var obj in objectsToActivate)
        {
            obj.SetActive(true);
        }
        foreach (var obj in objectsToDeactivate)
        {
            obj.SetActive(false);
        }
    }
}

I use this in my main game scenes as I'm constantly turning things on and off in the inspector and forgetting which ones should be enabled/disabled at startup.

Attach this to an empty game object in your scene and drag in things you want to enable/disable at startup. This script has an execution order of -1000 so it should run before anything else thus ensuring your objects will be setup when a scene loads.

Much more useful than having references to UI panels that need to be setup "just the right way" when you're always tweaking things.

Enjoy!