It's absolutely possible! I started at birth using a method called elimination communication (google it to learn more, it sounds nuts, but it works!) and you can use some of the same techniques with young toddlers. The most important thing about starting early, IMO, is to NOT force it and not to praise or shame at all.
Instead of praising my girls when they pee in the potty I tell them what they just did in a matter of fact way. I don't want them to think that it's a big deal because it's not... it's just what is done. We all pee in the potty. If you make a big deal about it then it can end up being a power struggle later on sometimes.
My older daughter was out of diapers without having accidents at 13 months old, so some children are definitely capable of learning to potty at your son's age :) I have friends who have used this method with their sons as well, so it doesn't just work with girls.
Feel free to message me if you have any questions or need help finding resources. There's a group called Diaper Free Baby and I'm a mentor through that group. They have many articles and resources and even groups that you can attend if there's one in your area so you can meet others who potty trained their children early.
Best wishes!
~B.
P.S. Most children need to pee immediately upon waking up from a nap or in the morning so that's a great time to set him on the potty and read to him or play with a special toy while he's on the potty :)