Source for event photography advice and tips?

I'm an experienced real estate photographer, but I've been given the opportunity to shoot a big event for the first time. I'm new to event photography, and I'm wondering if there is a good website (or maybe even this subreddit) that I can turn to for advice. Things from lenses to use, how/what to charge, what shots to get, etc...

It is a graduation event with a ceremony and the cocktails and food afterward. Total length of the event is going to be around 4ish hours, and as far as I know, I will be the only photographer.