For me, I wish someone had made me remember that there is time...
As an informed new dog owner you are bombarded with info about how critical the first few weeks are for setting good habits, socialising etc. This is true BUT you don't have to do it all in that time frame. I rushed to cram everything in (meeting all sorts of people and animals, grooming, swimming, obedience, walking, recall, being left alone etc) and got stressed when he didn't seem to take to something because I worried he would never get it/like it.
He's 11 months old and STILL learning. We had way more time than I realised and I needn't have got so worried. Only just last week he met cows for the first time, was spooked at first but then settled down with them. He didn't NEED to meet them before 16 weeks old to do that.
Also, every time he displayed a behaviour I didn't want (e.g. digging) I would worry that he would do that thing forever. They change all the time and his favourite past time one day is forgotten the next.
Patience, kindness, perseverance will take you a loooong way.
Oh, and take loads of videos. They are little puppies for such a short space of time that within 2-3 weeks he will be replaced with a bigger version. You'll want to see those videos of when he was small.