In this kind of fanfiction, Kakashi would probably make sure Naruto is comfortable first. He might tuck Naruto into bed, just like how a caring mentor would do. Then, he'd likely prepare some warm soup for Naruto to help him get better.
Kakashi provides a sense of stability. Naruto has a somewhat chaotic life, but Kakashi is a constant presence. He's like a father figure in a way. He's always there when Naruto needs advice or just someone to be around. This stability helps Naruto feel more secure and less alone in his journey as a ninja.
Well, Kakashi has a lot of unique jutsu. He could share some of his knowledge about them with Naruto. For example, he might teach Naruto some of his lightning - style jutsu in a simplified form. Also, Kakashi is good at stealth, so he could train Naruto in that area, which would be very useful for Naruto in both combat and espionage - like missions.
One possible plotline could be that Naruto gets seriously injured during a mission. Sasuke and Sakura, with their combined skills, take him in and nurse him back to health. They might have to deal with Naruto's stubbornness when it comes to resting and following medical advice. Sakura could use her medical knowledge, while Sasuke could provide protection and also train Naruto in new techniques once he's recovered a bit, strengthening their bond as friends.
There could be moments of frustration for Naruto, especially when Sasuke is fussy or won't do what Naruto wants him to. But Naruto's love for Sasuke would override that. Emotionally, Naruto would be pouring all his love into taking care of Sasuke, trying to give him the family he never had. And Sasuke, even as a baby, might show signs of his future strong - willed self, which could both amuse and challenge Naruto.
Kakashi might use his Sharingan to quickly assess Naruto's condition. He could then take the necessary steps to heal him, like getting the right medicine or using some basic medical ninjutsu if he knows any.
One heartwarming moment could be when Kakashi stays up all night to help Naruto train for a crucial mission. Another might be when he takes Sasuke aside after a tough battle and gives him some words of comfort and wisdom.
Taking care of Naruto might make Sakura more empathetic. She has to understand Naruto's pain and needs, which could make her a better ninja overall. As for Sasuke, it could break down some of his walls. He has to be vulnerable in front of Naruto and Sakura, showing that he's not just the aloof and brooding ninja. This experience might also make him more open to the idea of relying on others and being part of a team again.
One possibility is that Naruto would be extremely clumsy at first. He's not exactly the most domestic type. But his determination to take care of Sasuke would shine through. He might struggle with things like changing diapers or getting Sasuke to eat. However, as time passes, he would start to get the hang of it and form a really strong bond with baby Sasuke.
One common scenario is when Naruto gets injured during a mission. Sasuke, being the one to take care of him, uses his skills to heal Naruto or at least keep him stable until proper medical help arrives. Another scenario could be Sasuke protecting Sakura from an enemy's attack, perhaps even sacrificing himself a bit in the process. And sometimes, Sasuke might help Sakura in her medical research, providing her with rare herbs or knowledge he's acquired during his travels.