First welcome to both you and your son!
Like has already been said, there is a LOT of GREAT information here! I would encourage you to read, read some more, and then even read some more after that. As you are reading, you will learn a ton of new information along with solidifying some of what you already know. You will also discover questions that you didn't know existed.
By reading and increasing your knowledge base, you will be able to ask questions that will better address what you are trying to do/learn. Make sure to share what you learn with your son. By teaching him as you learn and build, it will help you to better understand the concepts needed to build a successful car. Enjoy your time building and bonding as that precious time slips away quickly.
Welcome and enjoy the ride! Congratulations on your pack race and good luck at Council.