When new people move to Cambodia, they might not know about things that are common or normal for people who live there.
For example, maybe they don't know that it's polite to take off your shoes before going inside someone's house, or that it's important to show respect to older people.
They might also not know about the different foods that people eat in Cambodia, or how to use the local currency to pay for things.
It's okay if they don't know everything at first, because it takes time to learn and get used to things in a new place. But they can ask questions and try to learn from the people who live there, to understand and appreciate the culture and customs of Cambodia.