Your trainer is an idiot. Ask for your money back.
Don't let your puppy on the sofa.
Don't over react by screaming or running away. A loud "oww" should get him to back off for a moment, then you can redirect onto a chew toy.
Short sessions of calmness. Downstay for 1-2 minutes with a reward at the end.
If she's old enough (and she looks it) corrections via a small prong collar and tab are appropriate. Short sharp pull down when...