The first lesson Buck learned was that he had to really look out for himself amongst all the dogs on the beach. He sees Curly assaulted by a dog she approached in a friendly way. As soon as she is wounded she is attacked by the entire group. She is quickly killed despite the efforts of Francois and other men to get the attackers off her. He quickly learns that he must always be vigilant.
He also learned to accept a harness and learned to pull, something that he would be expected to do for Francois from then on.
Another interesting lesson he learned was that of how to stay warm enough to sleep at night out in the open. He had tried to enter the tent and was chased out but had no idea how to get out of the freezing wind. Luckily he stepped through the snow into a hole that had been dug by another dog and he quickly saw how to do it himself.
As they get on the trail, he also learns to eat everything as quickly as he can. There isn't time to do anything but to wolf down the share that is thrown to him and to quickly steal from others if they are less quick to finish their own.