The primary aspect of the minhag of kaporos is to take the kaporos, the chicken, or preferably its monetary value, and give it to poor people. One is not allowed to use money to buy kaporos from maaser money.
If a person brings the kaporos chickens to their home, they have to be careful to observe the halacha that one is not allowed to eat before feeding their animals. One may drink however, and in fact one should drink before giving their animals to drink, or to the kaporos, in this case.
If a person did kaporos and afterwards the kapara became a neveila because the shechita was not a kosher one, he must do kaporos over again. If it was a treifa, there was something wrong with the chicken, there is a halachic discussion whether one has to repeat doing kaporos. If one is worried about this problem, he can do kaparos with money.
It says in seforim that a person should be wearing a hat and jacket when doing kaporos.