I want to get a puppy and register it as a service dog so I can travel with it?

I want the dog for protection and conpanionship as I travel but I don't know how to get a service dog card for it or what kind of dog to get. Some girl had a card for her dog that made it so the dog could go anywhere she went cuz it was a service animal. She said she sent 20$ and a picture of the dog to some online place and they sent an a picture I'd for the dog that she showed when people asked and they let the dog on the bus and in stores and everything. I also need suggestions on what a good dog to get would be. Thank you in advance and I have $ to take care of it so don't be rude and say if I'm traveling with it I won't be able to take care of it because I will be able to care for it just fine.