The other answers are very good, but I would add one word of advice:
Don't get hung up on the rules right now.
Rules are great once you've established a good understanding of them, but right now the form of role-playing is much more important than getting bogged down in every little nuance of whether a given skill governs a particular task.
You'll be looking in the rules a lot, but I would suggest if you can't find the answer in 30 seconds or less, just wing it and look it up later. Maybe each player who has a question you couldn't answer can jot the question on a piece of paper, then everybody looks up the answers between sessions and reports back later.
My gaming group many moons ago started with zero understanding of tabletop RPGs and this was probably our biggest issue. Some of us *cough* me *cough* were treating it too much like a board game where the rules are critical to understanding the game, and had trouble recognizing that it's not about rolling dice and crunching numbers -- it's about smashing some bad guys and saving the hapless villagers and rolling around in the loot afterwards.
Note this mainly applies during gameplay -- the DM should spend as much time as they can reading the rules right now and getting as familiar as possible with the nuances. But they can't learn everything in a week (or a lifetime, really), so they should just do what they can once you're playing to keep things running smoothly.
I would also recommend not spending too much time in the first character creation session. Some of your players may want to get every detail right, but remind them the character sheet is just an interface. The real character is in their head, waiting to come out during the gaming session.