One possible plot could be Naruto exploring the modern technology on Earth. He'd be amazed by things like cars and phones which are completely different from what he has in his own world. He might use his ninja skills in unexpected ways, like using his speed to compete in track races and becoming a local celebrity.
Naruto would likely be very confused at first. But his determined nature would help him adapt. He'd start by learning basic things like how to use money. Since he's used to a barter system in his world, this would be a new concept. He might also pick up on the local language quickly, as he's always been a fast learner.
No. Slavery is an immoral and unethical institution. Naruto, as a character from a series that promotes positive values like perseverance and justice, should not be associated with slavery in any way. Fanfics that involve such concepts can be considered offensive and against basic moral principles.
Well, there could be a story where Naruto lands on Earth and is mistaken for a superhero. People see his cool ninja moves and think he's some kind of new, amazing hero. He then has to deal with the fame and also the responsibility that comes with it. He might use his new - found popularity to spread the message of friendship and hard work, just like he did in his own world.
Obviously Naruto himself is the main character. But often, he'll interact with local Earth characters. Sometimes it could be a group of teenagers who befriend him and help him navigate the strange new world. They might learn from Naruto and Naruto will learn from them too.
Well, he might encounter the Nightsisters. Maybe he'll have to learn their unique magic or face their trials. He could also form an unlikely alliance with them against a common enemy.
Well, one possibility could be that Naruto is exposed to some extremely powerful and corrupting jutsu that slowly drives him insane. Maybe he starts seeing hallucinations of his friends turning against him and that messes with his mind big time.
This is a rather dark and unethical concept for a fanfic. Naruto is a character associated with values like friendship and freedom. However, if such a fanfic were to exist, perhaps it could involve some sort of dark magic or curse that forces Naruto into a situation where he has to deal with slaves. But this goes against the original spirit of the Naruto series.
He could meet a local superhero. They might initially clash because they have different ways of doing things, but then they realize they can learn from each other. For example, Naruto could teach the superhero about chakra control and the superhero could teach Naruto about modern technology and fighting strategies used in America.
One possible plot is that Naruto arrives in America and is initially confused by the different culture. But then he starts to adapt. He could use his chakra to perform amazing feats at a local circus or fair, becoming a local sensation. He might also encounter some villains who are after his ninja powers and he has to fight them off while trying to keep his identity a secret.