SceneLoads.cs
using Sandbox;

public sealed class SceneLoader : Component
{
	[Property] public string ScenePath { get; set; } = "scenes/gameplay.scene";
	[Property] public float Delay { get; set; } = 5f;

	private float _timer = 0f;

	protected override void OnUpdate()
	{
		_timer += Time.Delta;

		if ( _timer >= Delay )
			Game.ActiveScene.LoadFromFile( ScenePath );
	}
}