User Profile

Hi I am in Xcode in the interface builder storyboard trying to make a tic-tac-toe game. In an action I wanted when the user presses a button an X appears at a certain font size. I have looked for a long time around the internet and still couldn't find anything. I will be forever grateful if you could help me 😁.  @IBAction func testX(_ sender: UIButton) { sender.titleLabel?.font = [UIFont withSize(75.0)]; } I tried this it doesn't work.

As the title says as a beginner I want to learn how to make an IOS game that has gaming content sound etc. where would I learn how to do that? Thank you 😄