Answer:
Alfonso doesn't like the way he looks, and Amy is embarrassed by her family's traditions.
In the excerpt from Broken Chain, Alfonso isn't happy with the way he looks. He tries to change the position of his teeth by pushing them, and he worked out excessively so that he can become more fit.
In the excerpt from Fish Cheeks, Amy is upset because her parents invited her crush and his family over for dinner and her family's traditional ways are not as neat and proper as her crush's family.
(I hope this helps)