how to use better func Update ?

Hi,

First, I'm sorry for my level of English.

I know how to program in swift and I think to know how to use SpriteKit. I try to develop a game (a little bit like Factorio). And after many tests I find myself stuck.

I'm afraid I do not use SpritKit properly.

Here is my simplified architecture :

class GameScene: SKScene{
     var g = Data()
     override func didMove(to view: SKView) {
        print("Hello")
        backgroundColor = SKColor.white

        let home = Home()
        home.crea(G: &g)
        addChild(home)
    }
    override func update(_ currentTime: TimeInterval) {
          if(tsomeAction){
               let cell = Cell()
               cell.crea(G: &g)
               addChild(cell)    
               g.cells.append(cell)
             }

          if(g.cells.count>0){
            for i in 0...g.cells.count-1{
                if(g.cells[i].goal == 2){
                    g.cells[i].UpdateColision(G: &g)
                }
                if(g.cells[i].goal == 0){
                    g.cells[i].UpdateGoal(G: &g)
                }
                else if(g.cells[i].goal == 1){
                    g.cells[i].UpdateStock(G: &g)
                }
                else if(g.cells[i].goal == 2){
                    g.cells[i].UpdateMove(G: &g)
                }
               
            }
        }



    }
}

And this is one exemple of func in class Cell

func UpdateMove(G: inout Data) { // goal 2

        var angle = Float()
        let dx = goalPoint.x - self.position.x;
        let dy = goalPoint.y - self.position.y;
        angle = atan2f(Float(dy), Float(dx));
            self.zRotation = CGFloat(angle)
            self.position = CGPoint(x:self.position.x + cos(self.zRotation) * 1,y:self.position.y + sin(self.zRotation) * 1)



    }

For me this architecture is realy simple to use. But maybe is not the best way to optimise FPS ?
I would like to add some child to the Cells (exemple : the food collected...) But I think it's to heavy to use SKSpriteNode for this. What do you think ?

You have to imagine the game with thousands (if possible) "Cells" on the map.