He might learn a time - traveling jutsu. This would be really cool as it could allow him to go back and change certain events in the Naruto world, or gain knowledge from the past to use in the present battles.
Perhaps he could learn a jutsu that enables him to communicate with animals on a deeper level. This would give him an edge in gathering information and also in battle, as he could coordinate with animal allies more effectively. In the fanfiction, it could start with Naruto accidentally stumbling upon an ancient scroll that contains the secrets of this jutsu.
He could potentially learn the Flying Thunder God Technique. It's a very powerful jutsu that Minato was famous for. Naruto's already fast with his Sage Mode and Nine - Tails Chakra, and this would make him even more formidable in battle.
In fanfiction, Naruto learning the Vacuum Jutsu could be really cool. It might give him a new and powerful offensive technique. Maybe he'd learn it from an unexpected source, like an old hermit in a forgotten land. This could potentially change the power dynamics in battles he's in.
He could become even more powerful. The Vacuum Jutsu might allow him to defeat stronger enemies more easily.
If he learned a healing jutsu, he would become more nurturing. He could use this jutsu not only to heal his friends in battle but also to help the villagers. His reputation would change from just a powerful fighter to also a healer, and he would be more respected in a different way.
Well, Naruto learning Uzumaki clan jutsu in the fanfiction could lead to some interesting character developments. He might discover more about his heritage and how the Uzumaki clan's jutsu are related to his own abilities. This could also change his relationships with other characters, like how they view him now that he has these new skills.
Sasuke could be one of the people to teach Naruto new jutsus. They have a friendly rivalry and Sasuke has some unique jutsus like his Rinnegan - related abilities. He could teach Naruto some aspects of the Rinnegan's power, or at least how to counter it more effectively which could be considered a new 'jutsu' in a sense.
One possible plot twist could be that Naruto discovers a hidden aspect of the Hiraishin no Jutsu. For example, it might have a connection to an ancient Uzumaki clan ability that no one knew about. This could lead to Naruto being able to use it in ways that Minato, his father, never did.
A common plot element is the struggle with chakra control. Since fire jutsu requires precise chakra manipulation, Naruto often has to work hard on this aspect. For example, in many fanfictions, he might start by accidentally creating small, unruly flames instead of the desired large and controlled ones. Another element is the mentorship. Usually, someone like Kakashi or an older shinobi takes Naruto under their wing to teach him the fire jutsu.
In many 'naruto learns wind jutsu fanfiction', one plot point is Naruto's determination. He is highly motivated to learn the wind jutsu, either to prove himself or to protect his village. There's also the aspect of discovery. He might find a new way to perform the jutsu that no one else has thought of before. And, of course, there's the part where he overcomes his weaknesses related to the wind jutsu, such as not being able to generate enough power at first. This makes for an exciting character arc.
One popular 'naruto learns fire jutsu fanfiction' is 'The Flame's Ascent'. In this fic, Naruto's journey to master the fire jutsu is filled with intense training sessions under the guidance of Kakashi. He faces many challenges like controlling the chakra flow precisely for the fire techniques. Another great one is 'Fire in His Heart' where Naruto discovers an ancient scroll that helps him in a unique way to learn the fire jutsu.