I’ve had two of these procedures (10 years ago and last week) and the experience was exactly the same both times. But I was still a bit anxious last week, despite knowing what to expect, and that is completely normal.
I had a morning procedure so no food or drink after midnight. I had a small glass of wine with dinner the night before though I wasn’t really in the mood for it to be honest! So I think a nightcap - in moderation - would be fine.
Definitely have something to eat and drink at 7am - slow release carbs or whatever works best for you that’s easy to digest and will see you through the morning.
But you don’t need to do anything different in the meantime. The anaesthetic is a short and light one and one moment you are talking to the anaesthetist, the next you’re waking up from what feels like a very deep sleep and it’s all done.