What to get my son - Focus on C++ and soldering

I am so sorry for another one of these posts. But I've scrolled through for about an hour now and I realized I'm too clueless to know what to even be on the lookout for. My son's birthday is coming up and he really wants to learn C++ and practice with his soldering kit. I was looking at a Pi first, but some more searching led me to Arduino instead. Problem is there is just an absolute flood of information out there and I am at a loss as to what to take away from it all. I got him a portable monitor, mouse, and keyboard. But the actual computer and project part is still a struggle. Any good kits out there that would start him off right? He's on his school's robotics team, so he has interests there. And I was trying to get him to tell me a project, but he kinda shrugged his shoulders. He just wants to practice the skills, have some good equipment to learn with, and figure out a bigger project as he learns what is possible. Thanks again!