As a newbie- only one year out myself- my advice is to watch or try ANYTHING and EVERYTHING they will let you get your hands on! If something is happening in the unit, ask to be allowed to observe or participate in any way possible. Ask lots of questions, and listen genuinely to the explanations. Be curious about everything- new procedures, different diagnoses, etc. Once people recognize that you are interested and willing to dive in, they will begin to seek you out for new experiences. During my orientation and first few months on my own, I managed to be involved in all sorts of cool (and terrifying!) things such as codes, attending deliveries, in-unit surgeries, etc. Recognize your limitations- you don't have to be pushing epi at your first code or anything- but make sure to be available in any way you feel comfortable. In doing this, I managed to have a way better orientation than the other new grads I started with. They were always saying, "How come you got to do so-and-so?" The simple answer is, I asked!
My second piece of advice is one I was given at my job interview. I asked some experienced NICU nurses, "What is the one thing I could do here to make people mad at me?" Their answer was, "Pretend to know something you don't know." I have found this to be absolutely true. People will not belittle you for asking for help or information, but you will find yourself in LOTS of trouble very quickly if you don't seek out that information when you need it. The tiny lives we take care of are too precious to make guesses!