To put your best foot forward means to embark on an undertaking with as much speed, effort, and determination as possible, which is what the speaker wants the candidate to do.
Consider the staetement "The grove only takes the top thirty drama candidates from the two thousand who will be auditioning over the next few days, so try your hardest and give it your all.". Based on this statement, is "The grove only takes the top thirty drama candidates from the two thousand who will be auditioning over the next few days, so put your best foot forward." a true statement? Yes/no/unknown