For me the number one thing would be patience.
This was what I was going to say. This puppy is going to test you to the limits physically, mentally, and emotionally for the first few months. It's a lot like having an infant, only these infants run around and have teeth (and like to bite!). If you've never had a puppy before, you want to mentally steel yourself as though you're headed off to boot camp or whatever. It's a very hard task that sometimes will leave you on the edge of a breakdown.
At the same time, though, in the long run, it's incredibly rewarding to be able to experience a dog's early weeks and months and watch him grow and develop before your eyes, and basically spend his whole life with him (Minus the first eight weeks). I think raising a puppy is totally worth it- I did it and I tentatively plan to do it again when my dog passes on one day. But it's not like the movies, and it's not like adopting an older dog. It's going to take a lot of time and intensive training on basic things ("Don't chew electrical cords", "Don't lick electrical sockets", "Don't relieve yourself in the apartment- no, going to the next room where I can't see you doesn't count as 'Not in the apartment'
I remember sometimes at the end of days, my back would act up and I'd be on the floor unable to move while my puppy happily jumped around biting me for an hour or two. Of course, I have health issues to begin with. But it's not easy for anyone.
But a lot of things in life that are worthwhile are tough.
The other thing I'd say in a more tangible way is put the emphasis on house training right away. Get that dog outside a dozen or so times a day to begin with. If he's resting and stands up-outside. If he's sniffing or walking in a circle-outside. If more than 90 or 120 minutes elapse- outside. If he looks mildly suspicious- outside. If he starts to urinate, interrupt him and get him outside to finish. Praise him profusely every time he goes outsides and interpret him loudly every time he goes inside and then get him outside. I got my dog house trained within 3 weeks, though I had to reinforce for a long time after. Lengthy house training is the A #1 reason people have trouble with their pups. Somehow it all seems a lot easier once the dog isn't pooping on your carpet.
Also, if you want him to ride in the car with you regularly when he's older, start with short regular rides now with him riding on your lap and being petted. He'll develop warm associations and love the car for life if he's anything like my dog. If you wait to do it, he's less likely to take to it. Same as people mentioned about getting him out for short walks and socialized ASAP (Also make sure to get those first vaccinations quickly [there's a series of 3 in 3 months to complete the first year vaccinations and get him more fully protected], so he has at least some
protection from disease while he's out there).