puppy won’t eat or drink

first time to own a puppy here and we just got her yesterday from someone we know. when she was taken home, i gave her food and she ate all of it (even licked the bowl)!

when i woke up this morning, my mom told me that the puppy won’t eat the food and drink water or milk that mom gave. the food was different from yesterday so i tried to give her the same food from yesterday but she would just sniff it and not eat :(

• she keeps whimpering and i’m not sure why