I worked at a small firm in structured finance as a freshman (not LA, SF, NY, Dallas, houston... ) for three weeks, to test them out. I didn't get paid, I only got my travel and food expensed (which was <1000$). I was an alright intern, and basically I helped out with excel spreadsheets, making coffee, etc. Towards the end, I did some regression analysis but never turned in my results. I didn't return to do a full internship. I'm not sure if I did a good job, but I did get a friendly "how are you" email from my boss a month after I had told them I wouldn't be returning.
I'm at an IVY with a 3.9 and econ/math as my major. I have a bunch of research assistant jobs, but no extracurriculars. Should I put the internship on my resume or not? PM if you want more details.