Construct 2 or/and 3 can help teach the logic of programming.
You learn using logic structures (loops, using variables, ...) and also by adding plugins to your project can gain access to even further browser-based features.
Is Construct 2 proper for an 8 year old ? If he's alone, that might be rough.
The question is rather how the camp is organised and what is their education method, what will they be focusing on ?
Will your son have made a complete game at the end of the camp ?
I'm pretty sure it will be the case. Start yourself with the Beginner's guide and the next steps tutorial linked at the end of the beginner's guide to have a more precise idea of how Construct works and how it can be transmitted.
From there, you knowing your son better, will be able to decide whether he needs the boost prior to camp or not.