I wonder where can I find valuable information about iOS user interface guidelines. I can't find any information similar to the Android guidelines.
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
Unless I'm misunderstanding your question, there are easily accessible guidelines for both:
In case the links ever fail. Doing a search for iOS (or macOS, and so on) Human Interface Guidelines will typically get you there as well. This is how many of us would get to them before the sites (I think they were only available in PDF, and random tidbits throughout the documentation sites.)