How do I prepare for the upcoming internship?

Today, I officially accepted an offer at a lower middle-market investment bank, which I’m extremely grateful and excited about. I’ve been told I’ll most likely be placed in the M&A advisory group, but I’m not sure how to best use the next two months before the internship.

I’m a first-year student, and I’ll probably be the youngest person on the team. Since the work goes beyond just spreadsheets and DCFs, I’d really appreciate any advice on how to prepare beforehand and what to focus on during the internship. 

Given that it’s a smaller firm, I’m expecting to get more exposure and responsibility, which I’m excited about. At the same time, I’m a bit worried about not knowing something basic or overlooking something and making a bad impression. Any advice would be greatly appreciated.