Once you've played a game with a Mii, you shouldn't get tutorials again when that Mii plays a game a second time.
If you play a multiplayer game with at least one Mii that's never played it, everyone has to watch a tutorial. You can skip it by hitting the appropriate button. The game will also give a tutorial if you switch roles, such as a player in Zelda who has played as a sword-person switches to the bow for the first time.
Note that if a player OTHER than the new player skips the tutorial, the game will give another tutorial next time you try to play (This may only be true if the "new" player loses the game). Make sure that the new player is the one to opt to skip the tutorial. This is probably to deal with over-enthusiastic experienced players skipping the tutorial out of habit, when a new player doesn't know how to play. This might be what's causing unexpected tutorials since it isn't obvious.
If you use one of the guest Miis, the game will assume that's a new player and play a tutorial as if it was a new Mii. The only way to avoid this is to make and use Mii characters other than the guests. Keep in mind the above if you're using a guest Mii while the non-guest player(s) are the ones skipping the tutorials.
You can't turn off tutorials in general, only skip them when they appear until the game determines you've seen all the tutorials you need.
What's the specific situation you're experiencing that you want to skip the tutorials?
Yeah u can excluding Yoshi Fruit Cart because when u fail a gate Monita tells u about the obvious (Fruit with Flags must be eaten in order, warp gates will teleport u, etc) but TBH YFC is a terrible minigame anyway.
the saying YOLO (You only live once) is just an excuse of doing something idiotic.