Ask HN: How to get the most out of a structureless internship?

Hi HN, I've been working at a company for about 5 weeks out of a 6 month internship, and I feel a little lost. Normally, internship programs have a bit of structure behind them, designed to introduce you to core technologies. The company I'm working for just started it's first undergrad internship program, and I've been lucky to work for them in their QA department. My question is this: How do I make the most out of my internship so that when I'm finished I get a sense of satisfaction and my boss feels like I have contributed to the company? Thanks.