A great place to get started, is to have a side project, where you install analytics. And it gives you an opportunity to make sense of the metrics, what each means and what the customer is doing when it is recorded. You can then use the metrics to find areas of improvement, what does this data tell me, about what I am doing and how I can improve?
A side project is just such and say way to get started. And lets you naturally follow the areas that interest you.