please help!, i cant start 1 player mode only 2 player mode and i dont know why.

If you're not using a brand new save file, it will keep the player mode it was started with. Either pick a "new" file or delete one and you should be able to select it.

no, i am starting new game, unplayed and it doesnt work at all. mario 2, lost levels, and world work but 1, and 3 dont