First of all, thank you for replying to me. I import the project from VS, and it's a Xamarin project. The exact template can be found in iOS App General Single View App, when creating a new solution in VS. Edit: creating a project in Xcode works, and I can build it without any problems, both to my real phone, and to a simulated one.

Thank you for answering me! I will then ask on another forum.