Facebook API. Where to start?

Question

PHP

Hello.
Sorry for the probably very stupid question ... but there is no one else to ask (How to start working with the FB api? That is, I am aware of the documentation on the site, but the initial stages are
incomprehensible: - do I need to register the page or not?
- what type of application to specify when creating, or is it not necessary to create it at all? (how to get app id, secret id then?)
- will unauthorized users be able to use the application?
- which api is better to use Graf or PHP SDK?
- where can I read about all this ( preferably in Russian) or look at the source?
-If, for example, I want to get a list of friends .. what kind of implementation (I don’t ask you to write, but tell me .. describe in general)
I would be grateful for any help. Thank you.

Answer 1

-Do I need to register the page or not?

For some features, you need to register your application, for some you don't need anything at all.
What methods will you use.
For absolutely all your questions in the description there are answers with examples