I had a great supervisor, Brent Filson, at Lever. He was extremely helpful when it came to mentorship for the business field. He also offered really constructive feedback on my projects, progress, and things I could improve on. Being able to talk to Brent about the new business theories and frameworks I was learning made the projects where I could apply what I learned very exciting.
The Berkshire Business Interns program run by Lever also contributed hugely to my experience. Not only did I have two other college interns working with me day to day, I also had the opportunity to attend events with other interns placed (with the help of Lever) at internships throughout the Berkshires. The small team at Lever made working there a lot of fun.
What I wish was different
Because Lever is a small nonprofit, at times there weren't many projects. It took me a while to learn to utilize any lulls in workflow as a chance to learn more about business concepts in general / work on old projects in new ways.
Make the most of your time here! You may not have as many projects as someone interning at a larger company or in a larger city would have -- and that can be great if you'd like to learn deeply about the field you've found yourself in. I was lucky that my supervisor took on a mentorship role and was happy to supply me with books and online resources whenever I wanted to learn more about something or had a question about a process outside of my job description. I left Lever feeling like I had gained hands-on experience doing market research analysis and also a theoretical/overview/abstract understanding of how startups and investments work, along with charities devoted to economic development. This is a lot more useful than it might sound if you aren't as interested in abstract information--- by learning more about how the business field works in general, I realized I might be a lot happier and feel more challenged in the legal part of business transactions/economic development.
All of this is to say that, even if you realize midway through that you don't want to do market research exactly, there is still a lot to learn here, and something else may propel you on a tangential path later!