Who might Naruto meet in the 'Naruto finds a secret library' fanfiction?

He could meet the previous Hokages. Since the library is infinite, there might be records or even some kind of spiritual manifestation of them. They could guide Naruto further in his journey.

Naruto might run into a group of rogue ninjas who are using the bunker as their hideout. This would lead to a confrontation where Naruto has to use his skills to defeat them and protect the village from their potential threats.

He might meet an ancient sage who has been sleeping in the ruins for centuries. This sage could have a vast amount of knowledge about chakra and the ninja arts that Naruto could learn from.

Naruto could encounter a group of rogue ninja who are also after the treasures in the Uzumaki temple. Then he'd have to fight them off to protect the temple and its secrets.

He might meet an old hermit who has been guarding the temple for centuries. The hermit could have valuable knowledge about Naruto's parents or some secret ninja arts.

He might meet the spirit of an ancient ninja.

Perhaps in this fanfiction, the secret library is guarded by some sort of magical or powerful entity. Naruto, being Naruto, would try to befriend it first. Once inside, he could find prophecies about the future of the ninja world written in the books. This knowledge might put him on a new path of preventing future disasters and bringing about a new era of peace in the ninja world.

He might meet Hinata. She is kind - hearted and would surely be interested in the puppy. She could offer to help Naruto take care of it, like making a little bed for the puppy.

He would most likely meet his father, Minato Namikaze, and his mother, Kushina Uzumaki. These are the two main family members he never really got to know growing up.

He could meet some Pokemon trainers. They might come looking for the lost Pokemon egg and Naruto would have to decide whether to give it back or keep it.