At first, he would be shocked and hurt. Naruto values his team highly. However, he has a strong will. So he would quickly turn his feelings into motivation. He could start exploring new places to gain more experience and knowledge. He might also try to understand why his team left him behind, and use that knowledge to better himself and his relationships with them.
As he grows up, Naruto could become very angry. He might develop a sense of abandonment and this could fuel his determination to become stronger. He would want to prove himself to his mother, wherever she is. In this fanfiction, his anger could be a driving force in his character development.
In a fanfic, if Naruto is left behind by his team, he might first feel a sense of abandonment. He could then use this as motivation to train harder on his own. For example, he might discover new jutsu or ways to improve his skills. He could also cross paths with other characters who help him grow in different ways, like an old hermit who teaches him some unique wisdom.
At first, Naruto would likely be shocked. He has always been so loyal to his team, and this sudden betrayal would be a huge blow. He might stand there in disbelief, unable to process what's happening.
Naruto would likely be devastated. His old team was an important part of his early life in the ninja world. He might initially go into a state of shock, unable to believe that they are gone. Then, his grief could turn into anger, vowing to find out who was responsible and make them pay.
Naruto might initially feel angry. He'd probably think about all the times he's been there for his team and wonder why they left him. But then he'd turn that anger into motivation. He'd tell himself he doesn't need them and start working on his own skills even harder.
Naruto might initially be heartbroken. He's a character who values family and connection deeply, so rejection would hit him hard. He could go into a state of self - doubt, wondering what's wrong with him.
At first, Naruto would be extremely hurt. He has always considered Team 7 as his family, so their betrayal would be a huge blow. He might go into a state of shock and disbelief.
Naruto might initially be in shock. He's a very loyal person, so he wouldn't expect such a betrayal. He could try to talk to her to understand why she did it. For example, he might say something like 'Why? I thought we were in this together.'
Boruto might be in awe. He would probably look at Naruto with wide - eyed wonder, realizing just how powerful his father is.
Naruto could also feel a bit sad and lonely. He's used to being an outcast in the village, but he thought Team 7 would be different. So he might start to question himself. Maybe he'd start training on his own more, trying to become stronger so that they would have to notice him. And he might also try to find other friends outside of Team 7 to fill the void.