How do you respond to puppy biting and eating every single thing in existence?

I contacted my puppy trainer and she said to not respond to the biting and putting a chew toy in his mouth. I feel like I should say 'auw' or a firm 'no' if she bites harder. What would be the best way to respond to the biting?

And how do you respond to the puppy eating literally everything when outside?

For context: my pup is 8 weeks old