There are multiple conflicts Matt, or Matteo Alacran, faces in The House of the Scorpion by Nancy Farmer. (There are two types of conflict: internal conflict (man verses himself) and external conflict (man faces man, nature, or the supernatural).
One conflict Matt faces is the judging by others in the Alacran household because he is a clone. This is both internal conflict (Matt's feelings about being judged) and external conflict (the actual judging by others).
Another conflict is found to exist between Matt and Tom (external conflict). Tom keeps trying to take Matt away from Maria (Senator Mendoza's daughter and a girl her loves).
One final conflict Matt faces is between himself and the Keepers (the people who run the orphanage). (This is also external conflict.) Matt will not conform to the rules of the Keepers, and they punish him (they beat Matt with a cane).