Well, in some fanfictions, Naruto might start by finding suitable partners within the village. Since he is the last of his clan, he could look for women who are willing to carry on the Uzumaki bloodline. He may also use his influence as a hero to encourage others to support his clan - revival efforts, like getting the village to provide resources for the new Uzumaki generation.
One way could be through adoption. Naruto might take in orphans and give them the Uzumaki name, thus growing the clan in numbers. He could also look into any hidden Uzumaki relatives or descendants that might be scattered around other villages or regions. He could then bring them back to Konoha to rebuild the clan.
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.
One challenge is the lack of pure - blood Uzumaki. Since he is the last one he knows of, finding suitable mates with enough Uzumaki blood could be difficult. Also, the Uzumaki clan has a lot of enemies. Those enemies might try to stop Naruto from reviving the clan so they don't become a threat again.
In some fanfictions, Naruto might use a powerful jutsu he discovers or masters. For example, he could find a forbidden jutsu that has the power to bring the dead back to life. Maybe it's a jutsu that requires a great sacrifice on his part, like giving up some of his own chakra permanently.
In some fanfictions, Naruto might restore his clan by using a powerful jutsu to bring back the dead members. For example, a fictional super - level resurrection jutsu could be discovered. However, this would likely have many consequences and moral implications within the Naruto universe.
It could also affect his friendships. Some friends might try to convince him to let go of his hatred, which could cause friction. On the other hand, some friends might support his stance, which could lead to them being at odds with the clan. For example, Sasuke, who has his own issues with his clan, might react in different ways depending on Naruto's situation.
His relationship with Sasuke could be affected in a big way. Sasuke is very much tied to his clan, and Naruto's rejection might make Sasuke view him differently. It could either create a rift between them or make Sasuke question his own loyalty to his clan. As for his friends like Sakura, she might be initially shocked but then try to understand Naruto's perspective.
Well, first of all, Naruto would need to establish a strong base for his clan. This could involve building a new compound or renovating an existing one. He would then focus on training the next generation. In the context of harem fanfiction, his relationships in the harem could play a role in this. For example, his female companions could help in teaching and nurturing the young ones, passing on their own skills and knowledge. Also, Naruto would probably seek out any lost or hidden knowledge about his clan to give his rebuilding efforts a more solid foundation.
Naruto could start to focus more on building relationships outside of his clan. He would seek acceptance from his friends like Sasuke, Sakura and Kakashi. Their support would give him the strength to rise above the situation. He might also start to explore different jutsu and skills on his own, without relying on any clan teachings.
He could also try to find a new family or group to belong to. Maybe he befriends some outcasts in the village and forms a new kind of family with them. This new support system helps him cope by providing love and acceptance that he was denied by his own clan. He would learn that family isn't always about blood relations.
He could start by gathering like - minded individuals. Maybe those who share his ideals of hard work and perseverance, like some of the underdogs he befriended throughout his life in the original Naruto story.