As others have noted, the OP was not asking if it was a good idea. He has decided to do it and is looking for tips.
My thought is that the more you and the girl know each other the better. I think there is a big difference between doing a 12 hr overnight with a girl you have seen once for one hour versus a girl you have seen 6 or 7 times for multiple hours each time. Multiple contacts help develop familiarity which not only helps the sex but also helps the conversation between sex.
As for you specific questions about alcohol and breakfast, I would urge you to simply ask her. If you are paying a girl for a 12 hr booking, she wants it to go well just as much as you do. Also, 99% of providers out there prefer clients to ask questions before a booking rather than have misunderstanding during the booking. There is nothing wrong with saying "I have never done an overnight booking before - can I ask some questions? Like what do we do about about breakfast?" The more you ask her, the more you are going to understand her boundaries as well as the things she doesnt care about. You will also be able to talk through your own expectations. Maybe you wouldn't do this for a 1 hour booking, but when you are spending the money on 12 hours, you are certainly entitled to get clarity. I doubt any girl would mind the conversation.
I think it is also useful to talk about the number of rounds you expect to have. I know the idea is that for 12 hours, you can go as many times as you can muster, but what does that realistically look like. Are you young dumb and full of cum who can go 6 times and expect to be pounding all night? Fine, but does she know that? Do you know that your last round of the night is going to be a struggle to the finish, but your expectation is that she does whatever it takes? Fine, but does she know that? More specifically, are you paying her a flat rate for 12 hours not matter how much or how little you have sex? or is she spending 12 hours with you and you pay for the number of rounds that actually take place? Be clear. I think if she has a rough idea of what to expect, you are both more likely to be prepared and happy with the outcome.
Finally, you should give some honest thought to the logistics of sleep. When do you normally get sleepy? Do you snore? Are you sure? What size bed do you have? Do you toss and turn? What if she tosses and turns? Do you have a spare bedroom in case one of you cant sleep? If you want to have a nice breakfast and final roll in the hay before she departs, then you need to make sure that she (and you) can get a decent sleep. I understand that you want to wake up next to her, but i think it will be useful to have a plan B.
