At first you may find it difficult to keep up with the pace of the class. The idea is to keep the movement going without interruption. So try to start an exercise with the video and then adjust your movement according to the voice cues. If an exercise is new to your body, it may take some time to figure it out. So you may not be able to do the recommended amount of reps. And that's ok! Don’t feel the need to rush through it or to pause the video every time. Just complete fewer reps and move on.
We understand that training may seem a little overwhelming at the beginning, but the classes feel much easier with the repeated use. Try to take one class a few times and see how it goes.