Different animals have different requirements, but in general you should try to provide:
Basic car training: Try to make sure your pet is used to riding in a car and spending time inside a carrier crate.
Health certificate: Take the pet in for a check-up so the vet can verify they’re fit to travel.
Food supply: Pack their favorite snacks, but try not to feed the pet for 2-3 hours before they hit the road
Extras: If you can, also pack their favorite toys or blankets to keep them calm and comfortable.