He needs to take it in stages, first learn the vocab of whta constitutes whatever the syntax is of his preferred language.
I recommend C++ as it is useful for a LOT of different types of electronics, embedded, pc, servers, you name it.
Also UNIX scripting is very useful.
Then he should write very small programs that he can use to build into little functions for larger ones. Something like adding two numbers at first, really simple, like almost blindingly simple, just to get comfortable with the architecture of the language.
Then write something that is more complex, something like how to make a little calculator that does all sorts of functions.
He'll need at least one reference book (which I heard you said he has, but you didn't specify what type of book, so look into it... it's a bit of a tedious process to get decent textbooks into the squares, but if you buy it new and send it to them FROM THE PUBLISHER, he can get it, you probably know this, but someone else might be reading and they might wanna help someone learn as well, so they need to know)
Additional texts of note:
Data structures
Math books, especially linear algebra
Web Programming
Wireless Communications / Bluetooth
That'll last him at least a couple of years to really master. Beyond that, he needs to get a system of writing so that he's not having to use English constantly, as it will take a ton of time. I've seen people use something akin to semaphore, but it's not _extremely_ important unless he's older, and has used his hands a lot. Cramping sucks, and losing your ability to write is nicht gut.
Alright well, I hope this helps. Best of luck to your friend, and if he mentions a thank you, please tell him he's welcome.
It's altogether reasonable to imagine a technology that can and will remove greenhouse gases from our atmosphere, soil, and water.
In fact, there are research efforts underway to this effect as I write these words. This doom and gloom attitude is very likely exacerbating the root cause of what ails our understanding of how to combat the issue.
Perhaps if a more hopeful, unified understanding of what we as a society are doing (!) was spread by modern media, we could then determine what steps to take in order to fix said issue.
Let's remember that: yes, 400 ppm sucks, and yes, climate change is a problem because of greenhouse gas emissions, but also let us remember that we have scientific understanding to relegate the negative aspects and effects if and WHEN we decide to work on these issues with a more focused mindset rather than the aforementioned doom and gloom.
Would it not be more effective to focus on what is possible via concerted efforts rather than what those who benefit from click-throughs do to enjoy larger ad revenue?
Unreal would be technically more efficient, as it's backend is closer to the metal than Unity. Unity is good, don't get me wrong, in fact I wrestled with whether to respond, but nevertheless Unreal's rendering is just plain faster, and therefore will make for a more transparent experience for your final product. I am friggin tired, so excuse my non reference laden post, but if you put in 10 minutes worth of ref work, you'll see I'm right.