Hi, I was a part of the 'popular' crowd during my MBA and Finance degrees. I'm also an Engineer. I'll tell you what I noticed, take my advice or leave it. Some of it is a bit...IDK 'vapid, shallow' but it's what I learned getting my MBA and I graduated at the top of the class...
What are you wearing? Dress for success. I cannot stress enough how important your outward appearance is to you being asked to stick around to help with "whatever". Those are the moments when the groups form and you are asked out to grab a beer after class. Also go to every single after class gathering, even when you're tired, even when you really hate that one guy. Your next job could depend on the connections you make at the bar... Mine did :)
If you do not know how to dress consider an online dressing service like stitch fix. If you do know how to dress, then pick a style you've seen around NY, Berlin or Paris Fashion week in the last ~4 years and adopt that style for about 2 years.
During my MBA I was an IT guy so while most people wore dress clothes coming from their business jobs and undergrad programs, I wore jeans... Over time I still wore jeans every day but they were clean, fitted and I started wearing button downs instead of t-shirts and golf shirts.
When you pick where to sit in the class, sit with the most attractive people in the class. If it's a lecture hall survey the room on the first day and move the next. I don't care who was sitting there yesterday. If that new seat puts you near the people who draw eyes, then it's your new seat. I don't care if you think you belong there or not, it's your seat. I don't care if the most gorgeous girl in the entire world is there or if you're married with 18 kids. Sit there then use the energy those beautiful folks tend to generate from the attention they inevitably draw to pull the people you like into your circle. Bonus if they turn out to be really nice people, double bonus if you meet a pretty girl and make her your wife.