Micro Forums: how many could I create?

I think I have some background reading to do.

To be clear, we will create what amounts to an event that has a place and time. Then, we want people that look at this event (they can be public or private) to be able to chat about it. An example would be a company picnic where people might chat about things specific to that event. Right now it is a custom system that is very simple, just allowing a single thread with posts and replies. If possible, I would like to use Discourse to create small forums which might even be a single “general” category.

I plan to better understand discourse but not for a couple months.

Thanks,
Dave