A minor is entitled to have Miranda rights explained just as would an adult.
If you were detained (i.e.you reasonably did not feel you were free to leave) by the police and were suspected of committing a criminal offense under questioning, you should have been informed of your Miranda rights before questioning started.
Everyone is entitled to be read there Miranda rights regardless of their age or legal status in the country.
If you were detained (not free to leave) you should have been advised of your Miranda rights before you were questioned. Some agencies have individuals sign a form indicating they are giving up their Miranda rights.
However if you were not detained, for example the police called you on the telephone you do not need to be advised of your rights.