Looking good!
For me, learning about the world was the challenge at the beginning. When I first popped into the evac shelter I did even not imagine I was surrounded by possibilities. Teaching that the world is destructible and harvest-able for crafting is an important first lesson.
I like where you are going with the map as a good 2nd lesson. Someone mentioned the Triffids T as an important landmark because of its danger. Illustrating mushrooms blooming out of John’s eyes could help a newbie know to run from a fungaloid rather than just saying they are dangerous for it :). Teaching what lives in the world for another lesson.
Purifying my first glass of water was a challenge. For 20 minutes I scowled at the pot I had collected and tried a dozen different times to fill it with water so that I could boil it. Teaching what tools, charges and components mean in crafting (and teaching clean water and cooked meat specifically and where to get them) could be a good lesson.
Teaching about moves is also important. Understanding the mechanics of the turns started changing my perception of the game as obtuse and confusing to something more engaging. As I learned what moves were and how to use them against the creatures in the world I was able to immerse myself deeper into it. Yes, we need to point out that letting a zombie walk into a bush is a great way to fight them. (More than teaching moves as just moving, but how turns work too in your swings.)
Tailoring is super important in CATA; something that did not occur to me with skills like ‘cutting’, ‘launchers’ and ‘firearms’ drawing my eye on the list. Tailoring seems like a throw-away at first until you understand how important it is to repair and reinforce your clothes/armor. Maybe a before/after of t-shirt and jeans compared to a survivor suit could help - and throw a tailor’s tape around John’s neck to show how he got there. PS pointing out how to use the soldering iron and what scraps you need for the types of leather/plastic and how to get them is also important: I scowled at a tattered rucksack for 20m before I figured out how to get plastic chunks.
Getting into crafting a roof eventually could help. It isn’t mentioned anywhere that I know of, but you must build orthogonally and when you build a roof all the character sees is a floor. More scowling 
These were my big first hurdles. Pointing folks to IRC would help because that is where I ended up getting answers to most of my game play questions!
