One challenge Naruto might face is the intense study required. Medical ninjutsu involves a lot of knowledge about the human body, herbs, and chakra control in a healing context. Naruto isn't exactly known for his patience with studying at first. Another could be the emotional toll. He'd have to deal with seeing severely injured comrades and might struggle to keep his emotions in check while treating them. Also, some might not take him seriously as a medical ninja since he's been more of a combat - focused ninja for so long.
One of the main challenges Naruto might face is dealing with political intrigue within the village. There could be clans vying for more power and influence, and Naruto would have to balance their demands while keeping the overall peace. Another challenge could be external threats, like neighboring villages that might see Naruto's leadership as a chance to attack. Also, he would need to ensure the economic stability of the village, which includes things like proper resource management and trade relations.
One challenge could be overcoming his natural inclination towards ninjutsu and taijutsu. Since he's always been more focused on those areas, switching his attention to genjutsu might be difficult.
In this fanfiction scenario, Naruto would face the challenge of changing the perception of the Uchiha within the village. Since he is now part of the clan, he would want to show that the Uchiha are not to be feared. However, there would be those in the village who still hold grudges or suspicions towards the Uchiha. Also, Naruto would need to manage his relationship with Sasuke in a new way. They are now family, but Sasuke has his own path and issues. Naruto would have to find a way to support Sasuke while also upholding the values of the Uchiha clan. Additionally, he would have to face the internal politics of the Uchiha clan itself, which could be complex and full of power struggles.
One challenge could be adapting to the team's dynamics. Team 8 has its own way of operating, and Naruto is used to his own style with his friends. For instance, they might be more methodical in their planning, while Naruto is more of a 'jump - in - and - figure - it - out' type. So, he'd have to learn to follow their lead sometimes.
One challenge Naruto might face is getting used to magic. Since he's used to chakra - based powers, the concept and use of magic could be quite confusing at first. Also, the rules and culture of Fairy Tail might be different from what he's used to in Konoha. He'd need to adapt to the guild's way of doing things.
One challenge is mastering the Sharingan's abilities. Since Naruto is not an Uchiha, he doesn't have the natural affinity for it. He would have to learn from scratch how to activate it, control it, and use its powers like the Sharingan - enhanced perception and the ability to copy jutsu. Another challenge could be dealing with the potential side - effects. The Sharingan can be a strain on the user's eyes and chakra. Naruto already has the Nine - Tails' chakra which can be unstable at times. Combining the two could be a tricky balance.
He has trouble moving around. Without sight, he can't easily navigate the village or the forest. He might constantly bump into things. Also, in combat, he can't see his opponents' attacks coming. It's a huge disadvantage compared to when he could see.
One challenge could be Naruto's stubbornness. Naruto has his own ideas and ways of doing things, and getting him to listen and follow Kakashi's guidance might be tough. Another is dealing with Naruto's past traumas. Kakashi would need to help Naruto overcome his feelings of loneliness and being an outcast. Also, Kakashi has his own responsibilities and missions, so finding time to be a proper adoptive father could be a struggle.
He might face challenges like finding the right place to plant the tree. Konoha has a lot of regulations about what can be planted where. Also, he needs to make sure the tree gets enough water and sunlight. If it's a magical tree, he may not know exactly what it needs to grow well.
One challenge could be controlling the power of the Juubi. It's an incredibly powerful and chaotic force. Naruto would have to struggle to keep it in check so that it doesn't overwhelm him and cause him to lose control. If he loses control, he could end up harming his friends and allies instead of protecting them.