The Legend of Uzumaki Hiroto was a derivative work of Naruto, which told the story of Uzumaki Hiroto's growth and the stories of other characters. Uzumaki Boto Legend was different from the original Naruto Naruto Shimbun Legend, so it was considered an independent manga.
It depends on the specific plot of the fanfic. Sometimes he could be on a secret mission, in a hidden village, or facing a new challenge in an unknown location.
One of the main themes is love. Not just the mother - son love between Naruto and Kushina, but also how Kushina's love for Naruto can be a driving force in the story. For instance, in some fanfics, Kushina's love gives Naruto the strength to overcome great challenges. Also, the theme of sacrifice is common. Kushina sacrificed herself for Naruto, and fanfics often expand on this idea, showing how Naruto honors her sacrifice and what it means for his character development. In addition, there's often a theme of discovery, where Naruto discovers more about his mother and his own identity as an Uzumaki.
One interesting fanfiction could be about Mit Uzumaki and Naruto Uzumaki teaming up to face a new, powerful enemy that the Hidden Leaf Village has never seen before. They could combine their unique skills and family powers to protect the village.
In many fanfictions, Naruto might obtain the Uzumaki sword through a hidden inheritance. Maybe it was left behind by an ancient Uzumaki clan member and Naruto discovers it in a secret location, like an old, forgotten Uzumaki shrine.
Well, he could start a family with Hinata and have lots of kids, passing on his Uzumaki bloodline. Then, he could encourage his friends who have some Uzumaki connection, like Karin, to also have families and pass on their Uzumaki genes. He could also set up a school or training center in the Uzumaki land, teaching the Uzumaki ways of life and ninjutsu, which would attract orphans or those who want to be part of the Uzumaki clan.
A really interesting plot could be Naruto traveling back in time to the era before he was born. He could meet his parents and other important figures in the village's history. This would give him a chance to understand the roots of the village better and also learn some new jutsu or strategies that he could bring back to his own time to make the Hidden Leaf even stronger as a Hokage.
Naruto could also express his love in a more playful way. He might tease the reader a lot but in a loving manner. And he'd bring her little gifts, like a special kunai he found on one of his adventures or some flowers from the outskirts of the village. He'd want to make the reader laugh and feel special all the time.