how long is a puppy considered a puppy?

According to Rover it is a dog under 1 year, I believe.

It depends on breed and size, but in general, anywhere from a year to 2 1/2 years. Adjusting from puppy food to adult food starts about 6 months but it is always best to check with your veterinarian first.

Training starts the day you bring your puppy home, consciously or unconsciously. You should start potty training, crate training and teaching basic commands (sit, stay. come) the day you bring your puppy home. Your interaction consistency is reinforcing either positive or negative behavior. Just start slowly but be consistent and praise/positive reinforcement.