As a beginner, you are going to want a ski that is forgiving and friendly. These skis tend to be shorter and narrower than others, with a flexibility that makes them less demanding on the legs than more rigid options. If you are very light, you will generally need a smaller length of ski and vice versa.
Don’t be distracted by the flashy graphics or fancy technology that your friends might be looking at, or fall into the trap of being sold a higher level package because the skis might be newer or more high-tech. You won’t need anything too flashy on your first few trips, it’s about having a ski that will support and stabilise you, rather than a ski that’s all about the speed. Trust the shop assistant as they are normally well versed in the best skis they stock for beginners.