Help with first session

Hey, new GM here getting ready to break a group new to rpgs into Dungeon World and I'd like to make sure it goes smoothly!
The book stresses going in with only a handful of ideas and to build the world and story with the players in the first session. We're all really into that idea. I know some people like to prepare stuff before hand but I'd really like to learn to ask questions and use what they give you like a pro. Not only do I think it'll be more engaging to create the world together, it also seems like a smoother transition for players new to rpgs to ease into something that's being built slowly.

But how do you guys go from almost nothing to having enough going on to keep the first session moving? Maybe I'm worrying too much and by the end of character creation things will spin up pretty naturally, but thinking it out I can't see the process of how I'll build answers to questions into an engaging first session. Those of you who drop players right in with the "You're being attacked by ______! What are you doing here?" technique, how do you rev the first session up into the beginning of a campaign?

It'll be fine!

A neat thing I've heard of others doing and tried on my last session opening, to great success, is that something the characters could reasonably do during an adventure and then jumping straight to the last five/twenty minutes.  So, they aren't ambushed by bandits at the start, they're already in the heart of the bandit camp surrounded by enemy bodies (and at 3/4 hp maybe) as the Bandit King Thadius Orangeblood comes BURSTING out of his tent riding bareback on a dire beaver, trying to escape.  Does he?  Will he be back for them, or start recruiting people into a new gang (including someone's nephew?)... or maybe they slay him and his mount.  Are there dire-beaver-babies that need tending to / murdered?  You've got half an hour or so there easily - now pay attention to the characters.  Where are they at odds with each other, or there's the potential for conflict?  Did they enjoy depicting the slaying of the Bandit King or were they more interested in debating the future of the beav-lettes?  Play to what they played best.

Have their successes BE successes, but have complications arise going forward that threaten something else.  Once you get the knack for that the cold start gets easier. 

I'd like to suggest having a smoke / bathroom / coffee break shortly after all the characters are made up, when the natural 'This is why I'm cool, this is why you're cool, and this is why we'll probably (hate/love) each other' talk dies down.  Something spouted off during those ramblings will jump out at you or give you an idea.  Push it hard.  And if nothing does, throw Thadius Orangeblood at them (or drop them into some other 95% done adventure) and find out what they're glossing over and what they're embracing.