Good day my son is 2yrs old turning 3 January He's front 4 teeth contaminated and probably few inside as well Is it wise to extract now at that age?

See Dentist ASAP. Extraction is always the last resort when it comes to baby teeth. Baby teeth are important for the adult teeth. See your dentist or pedodontist as soon as possible for treatment. Please do not wait.
That depends. That depends on how bad the cavities are. If they can be restored by a dentist with a reasonable chance of success, then have them fixed, not pulled. If they are so badly decayed that they can not be fixed, then have them extracted the sooner the better. The longer you wait the greater chance of damage to the developing permanent teeth or of life threatening infections developing.
My word, no! If the baby teeth are infected the teeth must be be treated immediately, just as you would treat any infection. Extraction is a last resort, can adversely affect speech, function, permanent tooth eruption, and self image. PLEASE get your child to a Dentist ASAP. Considering his age and the advanced stage of his dental disease, best to see a Pediatric Dental Specialist, a Pedodontist. Go now!
Pediatric Dentist. Please take your child to see a dental specialist for children. Save the teeth. They are needed for speech development, eating, guiding the eruption of his secondary teeth, and his self esteem. And PLEASE take better care of his teeth by brushing them twice a day and avoiding sugary snacks and drinks.
Consult with a. dentist or specialist in children's dentistry. Sounds like it could be nursing bottle cavities. See dentist asap.
2 year old. Please see a Pedodontist (Pediatric Dentist) or even two for an evaluation. Make sure they are on the same page as to what is best for your son. Better to save teeth if possible but need to weigh risks of sedation, etc at that age. Why so many problems at his age? Make sure you understand why. Also get counselling by dentist going forward to prevent future problems.