Re: eating and drinking? Just do what you do in training., but substitute some "real food" for the bars and gels and stuff.
Eat, drink, and be merry. Most centuries are really just a big rolling party on wheels so HAVE FUN
. They usually are run as "touring rides" so rest stops and refreshments are plentiful.
If it is a big ride, the lines for the port-o-johns can be long (and they are stinky) so I always try to find a tree out in the country instead.
If you are not comfortable riding in groups you may want to find a group to ride with before hand so that you are not a hazard to yourself and others. Ride in a straight line and stay to the right of the road and all that stuff.
Good stories?
I met my SO while riding a bike. Our first "date" was 158 miles on a tandem.
We didn't kill each other.