How to stop puppy snarling/biting

Prefacing this with I know that puppies do bite, but the part I’m struggling with is knowing if I’m doing the right thing!

We’ve tried a lot of different methods to try and curb the biting, saying no, saying ouch, saying nothing, but putting him in a time out in another room or a pen is the only thing that seems to stop it. But struggling to know the right path, particularly when he seems to be going for us over all else, even when we have toys or out in the garden.

We recently had a session with a local trainer who gave us a house line and said to try and hold him away if he gets like it, to prevent rather than correct as he’s only 12 weeks, but worried about him pulling on his neck as even while trying to hold him at an arms length, he still pulls towards us, sometimes snarling, trying to bite feet, trouser legs, and hands if we’re sat down.

Any advice would be greatly appreciated, we want to be consistent with our approach, and we will keep with the line if it’s the right path, but interested in what people who’ve had this have done!