A puppy can be trained from about 2.5+ months old onwards with a professional or by you. Starting at a younger age, the puppy can actually learn faster than an adult and especially when it helps is before that puppy actually picks up any bad habit.

Here are some ways to avoid mistakes in your training.

https://www.wagr.ai/pet-guide/five-dog-training-mistakes-you-re-probably-making-and-how-to-set-them-right