Different breeds take different amounts of time. From what I've seen/been told, smaller dogs are particularly challenging. Puppy pads are a terrible idea as they do just encourage the dog to toilet inside.
The breeder also plays a huge factor.
An 'average' (although I would call it bare minimum in turns of responsible breeding) breeder should be sending a dog home 'clean' as a bare minimum. That means that within a few days the dog learns not to go in it's crate etc - and they will have done this by cleaning the whelping box rigorously the second a puppy does an accident so the puppies do not get used to playing or laying in their own filth.
A 'good' breeder (depending on dog size) will have started taking the puppy outside from about 5-6 weeks to get them used to going outside.
I use inverted commas simply because so many people don't seem to think breeders should have any input into toilet training - and I 100% disagree.
You have to be completely constant and on the ball. You cannot give them any reason to think peeing or pooing inside is normal. That means outside after every meal and every drink, rewarding when they do perform outside (use cue words) and as soon as they wake up/finish playing.
FWIW, my latest litter were nearly all completely housetrained before they went home at 8 weeks. The puppy I kept was clean overnight from night one and has had one accident in the house since (she's just over 4 months now) and that was a frightened tiddle rather than deliberate. From 5 weeks old I was house-training the whole litter and I was rigorous about cleaning the whelping box.
But Goldens (and retrievers more broadly) are particularly easily to toilet train - very rarely do I hear of one, even from a bad breeder, who is not mostly clean by about 14/15 weeks.