She could encounter other outcasts. There are likely other ninjas or people in the world who have left their villages for various reasons. By meeting them, she could form a new group, a sort of 'family' of misfits. They could travel together, sharing their skills and stories, and maybe even start a small community away from the traditional ninja villages.
One possible reason could be feeling ostracized. In the Naruto world, being different is often not easily accepted. As a female Naruto, she might face even more scrutiny and prejudice. Maybe she's tired of the constant expectations and the way she's treated in Konoha, so she decides to run away to find a place where she can be herself.
Another reason could be for the sake of protecting the village. Maybe he discovers some sort of threat that he believes he can only face by leaving Konoha. He doesn't want the village to be in danger because of him, so he runs away to draw the danger away from Konoha.
One reason could be that he feels misunderstood by the villagers. Despite all he has done for Konoha, some still hold grudges or are afraid of his power. Another might be that he wants to explore the world on his own terms, away from the responsibilities and restrictions of Konoha. Maybe he also feels a sense of loneliness there, as he has lost many important people and the village constantly reminds him of those losses.
He could run to the Land of Waves. He has a connection there from his early mission. The people there were friendly to him, and he might find some peace and acceptance among them. It's a place where he could start anew, away from the chaos of Konoha.
After running away, she could start a new life as an anonymous witch. She could use her skills to help Muggles in secret. She might use magic to heal the sick or prevent disasters in the Muggle world. This new life could give her a sense of purpose and also make her a more well - rounded witch as she learns about the Muggle way of life and how to integrate magic into it in a more discreet way.
Sakura might try to stop Naruto. She is one of his closest friends. She cares about him deeply and would be worried about his safety. Also, she would understand that running away is not the best solution to whatever problems he is facing.
Kakashi could be another one. As Naruto's former sensei, he knows Naruto's capabilities and potential. He would try to stop Naruto from running away because he believes that Naruto has a future in Konoha and running away isn't the solution to whatever problems Naruto is facing.
One possible plot could be that Fem Hiccup runs away because she feels out of place in her village. Maybe she's constantly compared to the traditional Viking ideals and doesn't fit in. So, she decides to leave and seek a place where she can be herself. Along the way, she might encounter new friends or foes, and have to use her unique skills, like her intelligence and dragon - taming abilities, to survive.
Maybe she'll come across a group of traveling merchants. They would introduce her to different cultures and items she's never seen before. This encounter could open her eyes to a world beyond her village and influence her decision on whether to go back or not.
One possible reason could be that he feels misunderstood. In the village, he has always faced discrimination because of the Nine - Tails inside him. People often look at him with fear and suspicion. So, he might run away to find a place where he can be accepted for who he is.