It depends on your taste preference, your health condition, and your health goals.
Not all juices are made equal.
When you first start off with juicing, it's best to stick to juices that you like. For most beginners, these will usually be the fruit juices that are sweet and delicious.
That ís perfectly fine because you're still getting used to the idea of juicing and learning how it's all done. However, the whole purpose of juicing is to provide your body with a variety of vitamins and nutrients.