このスポーツのルールを教えてくださいって英語でなんて言うの？

Simply asking what are the rules is a direct way to inquire about the rules.

Next you can ask what is ok and not ok to do as this is another way to ask what is allowed or prohibited during whatever game is being played.

Last if you slide into the question it can sound more natural so you could state your answer as follows :
I'd love to play but can you explain what is allowed.

That is further stating your interest in the subject and you're curiosity as to what is allowed or a detailed account of how the game goes.

1. "How" is used to enquire the manner in which something should be performed.

2. "Rules" include things that you should do and things that you can not do. This is where the expression "do's and don'ts" comes from.

1. To run someone through something =to practice something; to rehearse: "The director wants us to run through the first act this morning."
   If you run someone through something, you practice it or talk about it so the person will know it better: "A technician ran me through the data recovery process."
2. To give someone the lowdown on something means: give (someone) the lowdown (on something) To provide someone with specific or comprehensive details about someone, something, or some situation. "Give me the lowdown on what the boss is planning to do about the company's falling profits."

The first line is a straightforward question with on vagueness, requesting the rules of the game. Winning any game involves adhering to its rules. Breaking the games rules could result in disqualification.

In the second request, you have asked for the do's and the don'ts. The do's and the don'ts are basically the rules of the game. It means what you can do and what you can't do.

In the last request, you are politely asking him/her to take you through the rules (read you the rules) of the sport.

If you would like to tell someone that you have never played a sport and want to learn the rules, you can say something like "Can you please explain the rules of this sport to me please." or "Can you please tell me the rules of this sport, i have never played it before.".

When you want to ask someone to tell you about the rules of the game/sport they have asked you to play; then you may say this in the following ways:
-I don't know the rules. Can you please explain them to me?
-So, what are the rules of the game?
-Please tell me about the rules of the sport/game