The world would be in shock. The media would be filled with reports of his death. Civilians who had always seen him as a symbol of safety would feel vulnerable. There would be mass mourning in the cities he had protected.
The first birthday after his father's death was called the netherworld. Mingshou was a memorial ceremony held by children to express their grief for their fathers. The children could pay their respects to their father through flowers, gifts, incense, and wine. The atmosphere of Mingshou was usually low-key and simple, and it was not suitable to make a big fuss. However, the search results did not explicitly mention whether or not they could celebrate their birthdays. Therefore, based on the information provided, I am unable to determine whether my father's first birthday should be celebrated after his death.
Naruto might initially be heartbroken. He has always longed for his father's love and acceptance, so being disowned would be a huge blow. He could go into a state of depression for a while, withdrawing from his friends and normal activities. But then, Naruto is a fighter. He would likely start to question his father's decision and try to find out the real reason behind it, vowing to prove himself worthy if there was some misunderstanding.
Shikamaru would likely be the voice of reason. He would tell Naruto to think things through clearly and help him come up with strategies for dealing with the new situation. Choji might bring over some food to help Naruto out, as he knows how difficult it can be to take care of a child. Ino would be more interested in the child's appearance and would offer to help Naruto with things like shopping for the child's clothes.
Sakura would be devastated. She has known Naruto for a long time and has seen him grow from a loud - mouthed kid to a great ninja. His death would make her question everything. She might become more withdrawn and serious. Hinata would be heartbroken. She had deep feelings for Naruto. She might even lose her will to fight for a while.