How it goes will depend on your puppy. I brought an Akita puppy home by car years ago, and it was about 10 hours. Not fun. She was sick all the way. Would perk up and want to play every time we stopped, but the nausea resumed as soon as we were back on the road. She never was good in a car but, with many short trips to fun places later, got to where she could tolerate it without sickness.
Then I was involved in a trip that probably was 15 hours (Oklahoma City back to Denver area hauling horses) years ago with a Border Collie pup. The engine of the truck of the people we went to the show with blew up, and I had to cadge a ride home for me, my horse, and another friend who had come with us. The guy who agreed to take us had just bought the pup. So 3 people and a puppy in an old pickup with a bench seat. That puppy was wonderful. Never sick, slept most of the way. Was reported to be fine once home with new owner.
If the breeder will introduce your puppy to a crate, it will help, especially if you're going to be alone. They seem to settle better that way. The breeder of one of my current girls put a puppy-sized crate with door removed in with the puppies. They crawled all over it, chewed on it some, of course, went in and out at will, and occasionally one would fall asleep inside.