Question

The earth is currently moving around the sun all the object present on the earth are also moving then why we says that the object is at rest.

Answer 1

"A state of rest" is a relative term. Relative means - measured in comparison to the things around it.
When you sit in a train and sip from a cup of coffee, you can do so because the cup is still relative to you even though both of you might be hurtling through the countryside at 200 km/h.
For most experiments, objects can be considered "at rest" if they don't move relative to the things around them. But the "frame of reference" (the thing that you consider "stationary") does matter.
For example - if you sit in a car that accelerates, you might be "at rest" relative to the car, but you can feel yourself being pushed into the seat of the car by an invisible force. Similarly, there are measurable effects on earth that are due to the fact that Earth rotates about its axis (for example - the way air rotates around a low pressure region is a consequence of the rotation of the Earth), and even effects that relate to the motion around the sun (including the tides).
Physicists call accelerating and rotating frames of reference "non-inertial", and say that observations in such frames "give rise to fictitious forces" - that is, if you think your non-inertial frame is stationary, you will also think that a force has appeared out of thin air. Such as the force that pushes you into the seat of the accelerating car. Or the "force" that makes you spill your drink when the car goes over a bump (and your "frame of reference" suddenly accelerates).
But for many "in classroom" experiments, we can ignore all these things. Much of physics (and science) is about knowing what you can ignore, and when you can ignore it.