Hi and welcome.
Goodness, what a shock for you, and what a huge learning curve too!
The first thing you need to know is that there are 2 main different types of diabetics. Your son is a type 1, which means he needs to use insulin and you will both, in time, need to learn to count carbs (which includes sugar).
There are other diabetics who are type 2, and who often control their diabetes with diet and different medications from type 1s.
Apologies if this is too basic, but I don't know where you stand with background info at the moment.
So when you read posts, have a look at the avatar pic to the left of the post, and you will see that most people identify themselves as Type 1 or type 2 - and depending on that, they may be taking a different perspective, as an insulin user, or a diet controlled type 2. That should help you out in identifying information that applies to you and your son.
I am not type 1 myself, but I will tag
@mahola
Both she and her 11 yr old daughter were diagnosed type 1 recently, so she will know EXACTLY what you are going through.
Oh, and welcome to the forum!