Um i just bought i red eared slider like 2 days ago and it hasnt eaten a thing?

Juvenile turtles are usually voracious eaters, and in this case it may just be settling in to it's new home, turtles like routine and do not like to be disturbed much. I would offer it some live food and see if that does not change the situation, like minnows (no goldfish) earth worms, and night crawlers.