Lojban is likely to be very different to the kinds of languages you are familiar with — which certainly include English. Learning it may be easy or hard, depending on how well you understand the ideas behind it. There are not many words and rules that you need to learn to get into a basic level. You will get there rather quickly if you put a systemic effort. On the other hand, if you fail to understand some basic point, memorizing things will not help you much. In such cases don't hesitate to move on, and come back to it later. Likewise, some of the exercises are trickier than others (particularly the translation exercises).