One possible plotline could be that Kakashi arrives just in time to save Naruto from a powerful enemy's ambush. He uses his Sharingan to predict the enemy's moves and counter them effectively, allowing Naruto to escape unharmed.
In some fanfictions, there could be a plot where Naruto and Kakashi get transported to a different dimension. In this strange new world, they have to find their way back home while facing various challenges. Along the way, they learn more about their own strengths and weaknesses and how their partnership is crucial.
Perhaps a plot where Naruto's determination in the face of some sort of 'heat' - like a difficult situation in the village, and Kakashi is there to guide him. It could involve Naruto learning new jutsus under Kakashi's tutelage while also dealing with his own growing pains.
Well, in some 'kakashi teaches naruto fanfiction', there might be a plotline where Kakashi teaches Naruto how to better control his chakra. This could involve some really intense training sessions deep in the forest. Also, Kakashi could be teaching Naruto about the art of stealth and infiltration, skills that Naruto doesn't have much experience with but are crucial for a ninja.
One possible plotline could be Kakashi teaching Naruto some super - advanced jutsu that Naruto then uses to surprise his friends in a sparring match. For example, Kakashi might teach Naruto a special lightning - style jutsu that Naruto masters and combines with his Rasengan.
A great plotline could be that Kakashi, in raising Naruto, reveals to him the true nature of the Fourth Hokage's sacrifice. This would not only deepen Naruto's understanding of his father but also give him a new perspective on his own life and purpose. Kakashi could then train Naruto to live up to his father's legacy in a more profound way.
Another plotline could be the relationship between Naruto and Kakashi growing deeper. Maybe Naruto faces a personal crisis and Kakashi has to use his own experiences to guide Naruto through it. This could show a more emotional side to their master - apprentice relationship.
Perhaps a plotline where Kakashi and Iruka have to protect Naruto from the Akatsuki. They train Naruto intensively to prepare him for any potential attacks. At the same time, they try to keep Naruto's identity as the Jinchuriki of the Nine - Tails a secret from the Akatsuki members who are after his power.
One possible plotline could be that Neji is severely injured during a battle against a powerful enemy. Naruto arrives just in time, using his newfound Sage Mode powers to fend off the foe. He then uses his medical ninjutsu skills, which he has been secretly training, to heal Neji's life - threatening wounds. Another plotline might involve Neji being trapped in a genjutsu created by a rogue ninja. Naruto, with his strong will and ability to break genjutsu easily, dives into Neji's mind to free him from the illusion.
One possible plotline could be that Naruto has to go through a series of dangerous trials in the enemy's territory to reach Sasuke. He might face powerful foes and have to use new jutsu he's developed. Another plotline could be that Sasuke is in a coma, and Naruto uses his chakra to somehow enter Sasuke's mind and fight off the inner demons that are keeping Sasuke trapped. Maybe Naruto also has to convince Sasuke's friends from his time away to help him in this rescue mission.
One possible plotline could be Iruka and Kakashi trying to teach Naruto different ninja skills in their own unique ways. For example, Kakashi might focus on more advanced combat techniques while Iruka helps Naruto with the basic ninja knowledge. Another plotline could be them dealing with Naruto's pranks and how they discipline him in a loving yet firm manner. Maybe they also have to protect Naruto from some of the more dangerous elements in the ninja world that target him because of his status as the Jinchuriki.