To distinguish between Residential or Business addresses when importing orders. Start by creating an automation. The "Condition" for the automation can often be "Is Domestic=True"

The "Action" in the Automation will be "Set Verified Destination Address as Residential" this action will set the Residential Flag to either be True or False based on the result of the address validation

You will want this automation to run before any automations that set shipping services in order to correctly set a rate