ok to help you out a little bit here, best to describe what people might be needed for before they volunteer (not everyone might be familiar with the concept).
Assuming general hackathon (event or competition that usually span a single day or 2, sometimes overnight. People work in teams to solve a set of challenges using technology) setup.
Mentors : People with general knowledge, but not necessarily detailed. Can help groups to get started/brain storm possible ideas. General point of contact if someone wants help, which is usually helping people go thru the debugging steps (I’ve done this a few times and had no idea how to use the language).
Judges : Small group of people that goes around teams near the end of the event to judge/discuss projects with teams. Judges then meet up privately to discuss findings and start to rank projects based on some set of metrics, usually something like : Idea, effort, difficulty, does it work? (although not always as strongly weighted as some thing).
General helpers : Facilitate registrations, general queries, restock food/drinks (if provided), toilet/door monitors (if needed). Joint clean up afterwards.
Most hackathons have a dedicated person/team handling the IT and any media (presentations/audio/microphones).
Hackathons usually start with some presentation at the start, covering housekeeping, the challenges, sponsor messages, timetables. Most have some twitter hashtag for communication/advertising (twitter wall displayed on a main projector somewhere). Breaks are sometimes scheduled, which are additional presentation/talks, usually a time to remind people how to get help/make sure everyone is on track, also to advertise any group ‘workshops’ that might be running (someone explaining how to use xyz tech). Finally, there is the final prize/awards at the end, which is usually after some break (so final judging can happen).
You do not need to be technical to help out
Does that help ?