See the book "Program or be Programmed" by Douglas Rushkoff. It's about this idea, that you should know enough technical stuff not to be bamboozled by it. http://programorbeprogrammed.com/
The important step I found with my children was to recognise that they can control what a machine does, and indeed design a machine themselves. I think this is more fundamental than any specific technology.
Don't buy a computer yet. I'm sure you can find a used one, or let him access the one you already have. Get the free software Scratch, which is a programming language. You can make animals talk, make cars drive in to walls, or calculate sums, all by dragging shapes around.
Also try some web sites which offer two special things: big data, and communications. Think of a question and search the web to find the answer. Look at your neighbourhood in Google Maps. Send an email to your relatives and get a reply. (some privacy issues begin to arise with Internet communications)
For a bit of hardware fun, get a Velleman kit and solder the components together. And back that up with the creativity of making just anything new in Lego. That can lead to other projects, or assembling a computer from components.
I'm cautious, at that age, about robot kits that promise too much. They're either not customisable in which case you're not learning, or too flexible, in which case they're too hard for the age group. Which is why I'd start with software. But I'm also cautious about "educational software" which will only confirm the attitude that he is a consumer and can only answer A, B, C or D.
To thine own self be true. (If not that, at least make some money.)
