If both of their parents don't care they can date, they could not get physcial or have sex

Yes.
As long as no "sexual relations" happen.
That includes holding hands, kissing, etc.

The law varies from state to state. Going to a movie is fine but anything that involves sexually oriented activities is considered a felony in many states. Holding hands is on the OK side, anything that includes petting, genitalia, breasts and buttock is out.