I do not think you will get eliminated for not doing it, but when I enter the ring, I always pick up a trot, look at the judge and nod my head. You don't have to do like a formal salute with arm down like in dressage. Just a nod of the head. Even if a salute is not required, it is still good to let the judge know you a ready to go. Also beginner novice is ALWAYS timed. Sometimes at schooling shows the starter levels won't be timed, or if they do time it, it doesn't affect your school (no optimum time). That said, I have trotted an entire BN stadium course (green horse) and never got time penalties. The stadium time for BN is pretty generous. If you just go at a nice, steady canter, you will definitely make time.