As a child, Sakura was quite a different person; she was shy, timid and kept to herself. The other children often picked on her because she had a larger forehead than most kids and it resulted in her being somewhat depressed and she'd often end up crying on her own. It was on one of these occasions that she met Yamanaka Ino, a confident and popular girl.
Ino took pity on Sakura, feeling sorry for her because she was constantly being picked on. She immediately told Sakura that because she tried to hide her imperfection by covering her face with her hair, the other kids picked up on it. She gave Sakura a ribbon to tie her hair back with, telling her that she had a cute face that if she showed off with confidence, would make the other kids stop picking on her. Sure enough, the others didn't even recognize Sakura when Ino was with her the next day.
Both girls became good friends, Ino's influence bringing out the best in Sakura, but one day, Sakura came running up, telling Ino and their other friends that she had someone she liked. They guessed immediately that it was Sasuke, much to Sakura's surprise and Ino's distaste, for Ino had an interest in Sasuke also.
As the days passed, Sakura became more cheerful and independent. Her liking of Sasuke grew to the point where she decided to let her hair grow long after hearing that he had a preference for girls with long hair. Her crush on Sasuke grew so strong that she told her best friend that from then on, they would be rivals. After that point, they continued to bicker and argue, competing with each other on who would end up with Sasuke as well as who would be the better ninja overall.
The time came for Sakura to graduate from the academy and become a genin. Everyone in her year was separated into three-man teams and she was to be paired up with Uzumaki Naruto (much to her dislike) and Uchiha Sasuke (much to her delight). At this point in time, Sakura had become too confident in herself. She had high grades, she was good looking and popular and she did not like the idea of having to be with someone as lowly as Naruto, who was unpopular and had very low grades. She thought of Naruto as nothing but a hindrance, someone who enjoyed tormenting her and getting in her way. She honestly believed that there was no possible way that he could understand her and she herself couldn't stand to be around him. She ends up telling this to Naruto face to face, while he's disguised as Sasuke (it was his idea to transform into Sasuke to see what Sakura really thought of him).
Karma soon rears its ugly head as the real Sasuke showed up shortly after. Sakura told him that Naruto always got between them, because he was poorly raised. She went on to say that because Naruto had no parents, he was able to do whatever he wanted without any discipline and has grown to be selfish. This did
not go over well with Sasuke, who grew up through the later years of his childhood with no family either and ended up telling Sakura that she made him sick. Sakura, stricken by hearing this, wondered if Naruto felt that way too and decided that maybe she ought to be nicer to him.
Shortly after being grouped together with Naruto and Sasuke to create "Team 7," Sakura would meet her jounin instructor, Hatake Kakashi. This marks the beginning of Sakura's journey as a ninja and her growth as a character.