Maybe Harry decides to build a house in a magical forest. He uses his magic to gather the materials like levitating the logs. He might also face some challenges like protecting the construction site from magical creatures that want to play with the building supplies.
Neville could be another helper. He has become quite skilled in herbology. He could help Harry by creating a magical garden around the house. The plants in the garden could be used for protection, like thorny bushes that keep unwanted visitors away, or for providing ingredients for household potions.
Maybe Harry builds the house as a sanctuary for his friends who lost their homes during the war. He'd use his knowledge of magic and the help of Hagrid, who would supply some magical building materials. The house could have rooms that change according to the mood of the occupants, just like the rooms in Hogwarts.
Tsunade could play a crucial role. She could use her vast knowledge of resources and economics to secure the funds and materials needed for the fleet. Jiraiya, if he were still alive, would bring in his worldly knowledge and connections from his travels. He could help Naruto find rare and valuable materials from far - flung places for building a truly remarkable fleet.
Sasuke could be one to help. Given their history and Sasuke's intelligence, he might contribute some knowledge about energy manipulation which could be useful for the lightsaber's power source.
Sasuke would be a likely helper. Despite their past differences, they are comrades now and Sasuke has his own set of skills that could be useful in building a village, like his Sharingan - assisted precision in construction work.
In this fanfiction, Naruto might build a fleet to protect Konoha from a new and powerful sea - based threat. He could use his shadow clones to speed up the construction process. Maybe he'd recruit his friends with unique skills like Shikamaru for strategic planning and Choji for strength in lifting heavy materials.
In this fanfiction, Naruto could build a guild to train the next generation of ninjas in a new way. He realizes that the traditional village - based training has some limitations. So, he creates a guild where the focus is on individual growth as well as teamwork across different bloodlines and abilities. The guild might also attract some former villains who want to reform and contribute to a new ninja society.