He sounds very advanced and must be very enthusiastic which is half the battle with children of any age.
The key is to keep the enthusiasm going, doing things actively and through play as often as possible.
Your son will soon recognise cvc words (consonant, vowel, consonant) if you play with word cards. These will have the picture and the word on each card. You can get various types, including dominos, pair games etc.
You can have fun drawing the letters with character faces on them, giving him the sound of the letter rather than the name at this stage. So if he knows that C is ke, and a is aa (as in apple) an T is Te, you can demonstrate and he can pick up how to put these letters together.
If he is keen to learn and is having fun, I don't see any harm in him learning to read simple words at his age. If he loses the enthusiasm later, don't worry, just give him a break for a while. After all he has plenty of time when he is older.
Hope that helps.
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