Is soy de the only way to say I am from

Hola Rania

You can say "Soy de + country":

Or you can say "Soy + nationality":

You can of course say something like: "Mi país de origen es España - Mi país de origen es México. This literally means "My native country is..." But this would be a bit more unusual to use in a basic conversation. 

Saludos

Inma