You need to confess the kind of sin you committed and the number of times you committed it (or as near as you can guess, if you don’t know the exact number).
Usually simply naming one of the ten commandments will be too vague unless it is the specific sin mentioned in them, but the case you described might be ok. Actually, saying you disobeyed your parents is more specific than simply citing the commandment, which speaks of honoring your father and mother.
Partially I think this case would depend on what the matter is that you disobeyed your parents about. The more serious the subject, the more likely it would be appropriate to say specifically what you disobeyed them concerning. Maybe a good idea would be to have a general discussion with your priest, whether inside or outside confession, about what level of detail is appropriate for confessing different kinds of sins.