To meditate, you need the right understanding or you will make many mistakes. Meditation without understanding is very risky. You may know a little bit about meditation, but this is not sufficient to develop your practice over a long period of time. It is not enough to simply imagine what is best. Overcoming obstacles is about cause and effect and the knowledge that things are connected.
Conduct generally has to do with karma.
The specific behavior to be applied depends on the developed level of practice. In Vajrayana, samaya is important. Beyond the meaning of receiving the empowerment and practicing a certain buddha aspect, samaya means proper conduct. It is concerned with avoiding any behavior that could harm one's own practice. It is not right conduct to practice something before having successfully built the foundation.