I know there are different ones for different numbers of decks, different rules, etc. Is there a best one to start with (probably the version of the game most common in Vegas or the U.S. generally I would guess) that is the best to start off with because you will have to learn less deviations for the other games?

Also, is there an online simulator to let me set up and play this game so I can make sure the game matches exactly the basic strategy I am trying to learn? Thanks!