You should take her back to the vet if it is possible.
Not eating and drinking is not normal. It is common with many problems including infection. Being in a new and strange place can cause some dogs to not eat, but most dogs that have been in a shelter/kennel have learned to eat in new situations.Dogs sometimes don't eat for several days after being adopted, but they usually continue to drink.
You may be able to take her temperature using a human thermometer. Lubricate the end and put it in her rectum using gentle pressure to get it in 1-2 inches. Remove it after a minute. Normal temperature for dogs is 101 - 102.5. 103 is a low grade fever and 104-106 is the common range for dog fevers. Look at her gums. They should be pink, not white, blue or bright red. Press on the gum behind an upper canine tooth. It will blanch white with the pressure and be white when you first remove your finger. It should return to pink in 2 seconds or less. If it takes more than 3 seconds, it indicates poor circulation, which can be caused by dehydration or heart problems. If her temperature, gum color and capillary refill time are normal, you can probably wait until regular vet hours to have her seen.
You should be able to carry her outside. Put her down where she can urinate and defecate if she needs to. Give her some time to do this then take her back inside.
Take water to her and encourage her to drink by putting your finger in the water and then in her mouth. You can use an eyedropper or syringe without a needle to squirt small amounts of water into her mouth. You can do the same with dog food or small amounts of human food (chicken, beef, fish, etc.) to get her started.
Let me know if you have follow up questions.