How to train my dog to not like people til I tell him to?

Your question does not make sense

Not possible.

you can't train him not to like people, and nor should you want to, because he could become fearful and therefore start to bite. If your dog is naturally friendly, that's a good thing because it means you've treated him well, so he expects all people to treat him well.

You can only train him to be obedient to your command to 'stay' or to 'get down' if he is over-enthusiastic.

This way you will get a nicely behaved dog who will not rush over to people, but will be friendly to them once they come over and say hello.

Not like people until you tell him to? Hmm, that doesn't sound like a great idea. Not the slightest bit. Raise your dog to be antisocial and before you know it you'll have a massive liability on your hands.

Train your dog. Put him in a sit stay when around people, and only allow him to interact with the people when you release him, he is off command. And, don't let people touch your dog when he is on command. It shouldn't really be a matter of him liking people or not, dogs need to be socialized. But you can train him to wait until you allow him to. But, it only works if he is on command. If you have a fenced in yard, and let him out to play, he is off command. And if someone approaches the fence and wants to pet and interact with him, he is off command, and should not be reprimanded for interacting with people then.