A simple place to get morality without religion is to use your own experiences to determine what you should do.

Someone stole from you, you felt bad, so you associate stealing with being wrong. On and on.

HOWEVER, absolutism is never the way. Cause and reason for committing such acts have to be done.

Survival is a more forgivable reason to commit wrongs, as this is our only life. Same goes for anyone else a person might have done wrong to try and help.

Selfish reasons, such as deriving pleasure, not so much.

Knowing what is right and wrong is inherent by our experiences, under most circumstances [there's always outliers, maybe some masochists for example]. The reasons are the complex secondary layer that must be considered.