I'd recommend a novice taster session for your first time. It's a nice introduction in to track days. Also I know you won't be driving on track for 6 hours but that's a long time for the car to be pushed hard. It's also quite physical so you'll feel it after an hour or so.
Other drivers are ok. You'll have more powerful and more experienced drivers most probably so get ready to see Blue Flags.
As for insurance I'd get it. You may not have an accident but what would you do if something does happen?
The next time I'll do it will probably be in someone else's car. I'll hopefully be able to let loose a bit more. By that I mean an experience. I know it means a lot less track time but I want to try it that way.