Why is your yellow belly slider turtle not eating?

If you have just gotten your turtle, then don't fear, it may take a week or two for them to get accustomed to their new surroundings. One thing to look for, is if they are jumpy when you, or anyone else appears. Also if a change was made in its surroundings. If they are not jumpy, and are perfectly fine when you are around, then I advise you to look up a near reptile vet, and bring them in for a check-up, just to make sure nothing is wrong with your turtle.