Hi Ms Camille. I'm on lesson 7 of the beginner course. I often am not able to practice warmups regularly because either i'm busy or am surrounded by people(I'm not too comfortable singing in front of people). Will missing practice once or twice a week greatly affect my ability to complete the beginner course with an improved singing voice? Will it be okay if I just do 5 or 10 minutes of lip trills on days I cant thoroughly warmup?

Hi, Sunaina! Even a little bit of singing is better than none. If you're practicing a few times a week, that's great! Here's an article with tips for practicing quietly as well: https://www.30daysinger.com/blog/how-to-practice-quietly-how-to-sing-better.