That is not correct. As an OCdt, you are an "Officer", but not a "Commissioned Officer". You are not supposed to be saluted. NCMs *should*, however, address you as "Sir". At your unit, Cpls and MCpls should generally treat you with respect, for example, by not yelling at you in front of troops. Instead, they should quietly take you aside and say "excuse me Sir, but...".
An OCdt, or 2Lt should always, of course, listen carefully to the advice of all trained NCMs.
On course, it's a different matter. OCdts and 2Lts are untrained officers, and on course we're simply "candidates".
But a Private certainly does NOT "outrank" an OCdt, under any circumstances.