First try to figure out where you want to end up, not where you're starting from. Let me explain: if your goal is to do relaxed mountain hikes maybe with friends, cross-country skiing is perfect. But if you want to go off-piste and have fun doing some fast turns, then alpine skiing is what you need to do. It's not that one is easier than the other for beginners, it's just a completely different thing.
The real detail that nobody's told you: in Livigno you'll have different slopes and terrain depending on what you choose. They teach you alpine skiing directly on the ski slopes, with the lifts, meaning in the real situation where you'll actually use it. Cross-country skiing on the other hand is often learned in flatter, more controlled areas, which is nice for learning the technique but then the transition to real practice is different. If you really want to ski right away, alpine puts you straight into the actual context.
Also consider that the equipment is pretty different, and if you change your mind halfway through winter you can't really use one type of equipment for the other. I'd say try both maybe in two separate lessons, if your budget allows it, and figure out right away which one you like better. After the first lesson you already know if it's your thing or not.