Is anyone able to better help me understand the Mastedon Instances?

I'm under the impression that they are similar to subreddits in reddit, and so I had joined this instance since it seemed more general than specialized, but now i'm unable to find the rules/guidelines of the instance.

Also.. Home & Local, I assume Local is everyone on this instance, and Home is only my feed/followers/personal responses etc.?

Sorry for the noob questions