I think that the best way to be introduced to a new game system is through a one shot adventure using pre-generated adventures.
The reason I feel this way is I’ve done a few Traveller one shots with new players and once the characters were handed out and the story started people can learn how to play the game on the fly.
This is especially true when running scenarios like Traveller Flatlined or the Call of Cthulhu Dead Boarder. The adventures are designed to showcase game play and game mechanics while having a kind of box to play in.
Once a person enjoys the game as it is, then sit down and learn how to create a character, and learn the finer points of the game.