I would also be asking the seller for a refund! When a goat dies within 24 hours of you taking possession, the issue existed before you got it. I would also try to get the dead goat sent off for a necropsy to see what killed it. As Babs said, YES, you should be worried about the other one. If the first died of cocccidiosis (cocci) then there's a real good chance the survivor has it as well and it kills fast. The only way to know for sure is to get a fecal done (bring the goat with you if you can) by a vet or at a vet's office or by someone who knows what they're looking for.
Really sorry you've started your journey with goats on this very sad note. If you can get the survivor a goat friend, it would be best. They really do better being with another.
Really sorry you've started your journey with goats on this very sad note. If you can get the survivor a goat friend, it would be best. They really do better being with another.