I seem to struggle with the pace of the class

Please try STRETCHIT classes labeled as Difficulty 1 (the difficulty level is indicated by lightning symbols). Those classes run at a slower pace. The idea is to keep the movement going without interruptions. So try to start an exercise together with the video and then adjust your movement according to the voice cues. In case a particular 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 it’s ok! Don’t feel the need to rush through it or pause the video every time. Just make fewer reps and move on. You are already awesome and you will totally rock it soon!