I’ve heard from other parents that you can’t choose when to do it - they will be able to when they’re ready, so if you start early you’ll just have a longer training process. Wait for the signs as said above and follow their lead (I’m not sure what following their lead looks like yet!)
Hello, I’d check out the ERIC website. They are a bladder health charity and have tips on potty training.
There are some good indicators of readiness on the NHS website, but at the very least I'd suggest when he is able to tell you when he is going for a wee or poo. My little girl is nowhere near but I have introduced her to a potty only to get her familiar with it, practice sitting on it herself, and if I know she is pooping I will put her on it to form an association there. But I know we are nowhere near the real thing yet and I'm not stressing about it!