It is tempting to act like you are way more experienced than you actually are and have a wealth of knowledge behind you. As you sit in your office, given a task that you don’t really know how to handle, you may appear calm on the outside but on the inside, you are screaming, “OMG!!! WTF do I do now?!?!?” Instead of spending hours on the task - from the get-go - ASK QUESTIONS. As someone once said, “It’s better to ask all the questions, upfront, because people may be less inclined to help later on.”
Of course, first and foremost, be resourceful - gain as much knowledge and insight into a task as possible. With a pen and paper in hand, after digesting your brief, pinpoint what you understand, what you don’t, and formulate some questions to ask.
On a side note - an internship is also your time to absorb as much information as possible. Squeeze as much as you can out of it, and ask away - even if you think your questions sound profoundly simple.