The Cunninghams are a poor farming family in Maycomb. They are hard-working, but are not aware of many social cues, as they spend most of their time working on the farm. Walter Cunningham Sr. is a good man overall, but gets swept into the racism and hive-mindedness of the town.
The Ewells are also a poor family in the area, but do not have a good reputation in Maycomb. They live in a run-down part of town, their children only go to school the first day of the school year each year to sneak their way around the law, and their father is known around town for being a low-life. This proves to be true in the courtroom scene, when we find that Bob Ewell is also an abusive liar.
B. Success because he is triumphant in winning
Nendo is basically Saiki's sidekick. He's not very smart, and he thinks Saiki is his best friend, even though Saiki doesn't like him. Saiki also can't read Nendo's mind. I belive yare yare means "Oh my," or something along those lines.