How did people in aryan society enter a certain caste?

In the case of Aryan society the inherited the castes. That means they are born in a caste. They will get the caste from their parents. There is nothing like changing the caste as one wants similar to modern days.

1.  go out into nature and commune with the divine2.  experience real solitude to truly perceive nature3.  realize that individuals are meant to learn from nature and transcend it4.  think of nature as a symbol of the divine