Seconding the points about listening to the AP's - it's a good way to internalise how the game should "flow" and "feel", as wanky as those terms are. Brutalists uses an older rules iteration, but the negotiation mechanics it uses are basically identical.
As for job lines, I think the GM section does a fairly good job of breaking down all the important bits and rolling up a basic framework is easy. When I was running an IRL demo game it was an hour's work on a laptop in a Starbucks to churn out the basics of three jobs (services, prices, competition, legs and complications) with fleshing out taking a little longer but being a pretty painless process. The main issue is probably just navigating the very early document. Also, listening to the (many, many) podcasts will help you get an idea of what sort of thing a job could be and, again, how you can structure things etc.
(I'm actually working on a bundle of 'demo jobs' right now, which Aletha has been giving me some great help on, for exactly this purpose. If you'd like I could PM you a Google Doc link.)