You can try and teach everybody to play a new game by having them read the rulebook. But that doesn’t help much. Even with the simplest of games, it is hard to take in all the rules at once. When we listen to the fifth rule, odds are that we have forgotten the first one and have to start over.
Instead, it is more effective to have people play the game and learn the rules as we go along. Once we start playing, the rules appear one at a time and in the right context. This makes it far easier to understand them all.
The most effective way to learn the rules is to merely start. It is daunting to start without knowing all the rules, but it is often the easiest way forward.