Both excellent answers.
I would add the following:
Focus on the customers (even if they are internal). How will they be using what you are doing? Ask them if you don't know. People love that you are interested in their needs and will gladly tell you. Even if your task is "narrow" at first, understand how it fits in the bigger picture.
Try to think in terms of solutions, not just questions when you don't know what to do. Try to bring your manager your best shots at how to solve a problem. This is where knowing your customer's needs and wants can be helpful, as the answer isn't always a technical solution. By the way, your manager is a customer of yours too, so know his/her needs and problems he/she faces in the organization. You will really separate yourself as a technical person and your manager will appreciate and be happy when you come to visit, which you should do proactively, not just when they ask.
In every job, there is some level of vagueness and non-definition. Less so at the entry level, very much so at senior levels. In fact, I could argue that the ability to handle more and more ambiguity is what defines a senior contributor. Seeing the big picture helps you give structure when you don't know quite what to do. Don't be afraid to ask questions and if the answers don't help you, keep questioning. If the organization you find yourself in, isn't receptive to your questions, find one that is. As you gain knowledge, try to apply what you know, to form the question in a way that is more readily answerable, as opposed to "I don't know what to do" (which may very well be your feeling).
Make friends at work. Be open to interactions that are not just business oriented. People like to help people they like. Approach senior people too. They have a need and desire to help younger people as they end their careers.
When people are not helpful, assume they are confused themselves or their are other issues in their lives not related to you. Keep trying (in different ways). Don't assume they just don't like you.
Be broader than your role, whatever it is. Be the one who non-technical people approach to explain. If you find yourself in a very narrow job definition, do more. Either the organization will appreciate and acknowledge you or you bring that broader experience to the next place. And, you'll enjoy what you do more.
Best of luck.