First of all: digs about grammar and spelling are almost never on-topic in these forums, and they're particularly unwarranted in response to a question about first steps for beginners. If someone's spelling or grammar is so difficult to read that you need to ask for clarification, do so kindly and carefully; otherwise, either address the content of the post or say nothing.
I second the recommendation of the No Starch Press books (https://www.nostarch.com/
) - I've heard only good things about them.
My all-time top recommendation for an enjoyable, all-round introduction to Raspberry Pi, particularly for learners of around that age, is my colleague Carrie Anne's book, Adventures in Raspberry Pi
). It will get your son up and running, and you can see which activities appeal to you both most and which you'd like to take further. You'll probably find lots of our own "Learn" (https://www.raspberrypi.org/resources/learn/
) and "Make" (https://www.raspberrypi.org/resources/make/
) resources suitable, too.
Many children love discovering how to do amazing stuff in the Minecraft world by programming in Python, and Martin O'Hanlon's Stuff About Code
) has some great resources for that, as well as links to more elsewhere.
I hope you both enjoy whatever resource you choose to start with!