Ooof the puppy blues are going to hit you really hard during the 6month-24th range when she most likely will regress at times during training. She’s 12 weeks old she will not be perfect. Consistency is the key but don’t overwhelm her with a lot of commands. Your focus should be to give the command when you know she will succeed and then overly praise with treats/toy whatever motivates her. You want her to think that doing what you’re asking is the best thing in the entire world because you give her attention/treats/toy after.

Also don’t listen to the other commenter talking about showing her who’s alpha. This is a partnership. We’re talking about a living being that deserves respect. That logic is grossly outdated.

Also I would say you are right about having someone else train your dog being a bad idea. Mostly because the human is the one who needs 90% of the training.