Well, it would make sense for some of Dooku's fellow Jedi from his early days to be in the story. Maybe Eeth Koth or Plo Koon. They could provide a contrast to Dooku's path. And on the Sith side, Savage Opress could be included. He had some interactions with Dooku. Also, Anakin Skywalker might make an appearance, as Dooku played a role in Anakin's journey, especially during their duels.
Yoda is wise and experienced, while Baby Yoda is more innocent and curious. Yoda's wisdom would likely guide Baby Yoda in his actions. For example, when Baby Yoda is about to make a hasty decision, Yoda's calm and collected nature would make him pause and think. On the other hand, Baby Yoda's curiosity could inspire Yoda to see things from a fresh perspective. Maybe Baby Yoda discovers something new about the Force that Yoda had overlooked because of his long - held beliefs.
Well, one plot could be that Yoda and Baby Yoda are on a mission to find a special crystal that has a strong connection to the Force. They encounter different species on their search, some friendly and some not so much. As they search, they also have to deal with the Sith who are also after the crystal. The two Yodas have to use their wits and the Force to outsmart the Sith and claim the crystal. Another idea is that they are in a situation where Baby Yoda's powers are being suppressed by some dark Force - based technology. Yoda has to figure out how to remove the suppression and in the process, they learn more about the nature of the Force and how to protect Baby Yoda from such threats in the future.
Often in Star Wars novels, there are antagonists. In the Yoda novel, it could be Sith or dark side users. They would be the main opponents of Yoda and his allies. Their presence would create conflict and drive the story forward. Yoda's interactions with them would show his strength and wisdom in combatting the dark side.
One great 'anakin dooku fanfic' is 'The Duel Unseen'. It offers a unique perspective on their relationship and the events that could have happened between them.
Dooku died at the hands of Anakin Skywalker in the novel. Anakin, under certain circumstances and influenced by various factors, was the one who ended Dooku's life. This event had far - reaching consequences for Anakin's own character development as well.