How does the acceleration time graph show if and object is speeding up or slowing down? Is it possible to find the answer without any deep calculations? If yes then how? Like how can I find the instantaneous velocity? Using accelration time graph?, and how can I show if the object is accelerating? Cause the graph just shows me if my delta velocity exists it doesn't tell me if my velocity is going to zero of something else!
It depends on the instantaneous velocity. If the acceleration has the opposite sign then the velocity, the speed will be getting slower at a given time, and if the acceleration is the same sign as the velocity at that time, the speed will be getting faster. Of course, if the acceleration is $0$, the velocity isn’t changing. So, just the acceleration in the graph won’t tell you; you also need to know the velocity.