He realized later that it had begun long before that. It had already begun on that day when he first wrote his age in two ciphers and his cousin McCaslin brought him for the first time to the camp, the big woods, to earn for himself from the wildness the name and state of hunter provided he in his turn were humble and enduring enough.

1. It 指猎熊️这件事。

2.before that：指那天早晨。

3.his age in two ciphers:指他刚满十岁的时候

4.the big woods:camp的同位语，指大森林。

5.provided:是连词=if，如果，假如的意思。

6.in his turn:轮到他了。

翻译：他后来意识到猎熊这件事早在那天早晨就存在了。当他刚满十岁的时候才参加猎熊大会，他的侄子（年纪比他大，辈分比他小）第一次带他到森林里（猎人们）的帐篷。假如到他是相当虚心吃苦，那么他也可以成为一个猎人，能在这原野里替自己挣的一个猎人的名声和地位。