10km/h is very fast for a beginner and likely unsustainable for more than a couple of minutes, I would expect most people to be starting around 5-6km/h if they’re a healthy weight.

I think the best piece of advice is START SLOW. way slower than you think. And run for way shorter than you think. Even if your lungs and muscles are fine, if you haven’t ran for a while then your tendons certainly aren’t. You won’t know until it’s too late and then you’ll be out of the game for weeks or months. If you can run on grass or a softer surface your body will thank you, running on concrete is brutal until you’re used to it.

There’s probably programs than you can follow that introduce you to running, I’d follow one of those.