Congrats, first of all!
Secondly, as a non-tech - you have to kind of prove your value. Come with a clear idea and why that idea is valuable. Then let people know your role. Do you do UI/UX design?
Hackathon's are for those that do... they work, they make something. If you don't have a specific skill set and are just hanging around with ideas, you'll be left in the cold fast.
Here is my experience as a designer last year. I tried to do some design strategy and thinking with my group before agreeing to the tech specs - they were not interested AT ALL. I found my 10 years of running design teams was useless. Someone started building the UI/UX without even a discussion. We didn't win. Usually, in app hackathons, the person with the best thought out, and most understandable expression of what you want to get across... wins. That means, you DO NOT have to be the best coder to win, unless it's a code specific hackathon. Like compression algorithms or something.
My point, go with teams that VALUE your talents and input. A lot of times, it's good to pick your team mates in advance. There should be a chat room or some way to connect before the day.
Good luck and it's going to be a lot of fun!