Which language is right for you depends on your experience, skills, and the specific type of iOS app you want to develop. If you are new to iOS development, I recommend starting with Swift. It is the primary language for iOS development, and it is relatively easy to learn. If you have experience with C#, Java, or JavaScript, you may want to consider using one of the cross-platform frameworks, such as Xamarin or React Native. This will allow you to write code once and deploy it to multiple platforms.