Welcome to IA arun...
Let me try to answer your questions..
1)How to fit the whole equipment to make it ready for fishing (any document is there or the tackle which i buy will come with instruction sheet?)
As per my knowledge, you can use a low profile spinning with telescope rod which will be very easy to carry.
2)How to change the lures or bait fastly in case if the fishes were not responding to one particular lure.(for ex from earthworm bait to frog bait).
Check the "Fishing knots" in Google. You will find your answer easily.
3)can't we fish without a fishing rod?(just using the hook and lines tied to a wooden pole)Note:this may be a silly question.
Wooden pole is a rod itself

but it is possible without rod.
4)what is the difference between spinning and bait casting?
In short, the spinning real is easier to cast then the baitcaster. They are set up different. The baitcaster's line is put back on the spool of the reel horizontally, the spinning real it is vertical to you. The spinning reel can use lighter lines and smaller lures.
5)My grandpa use real frog,lizard,fried chicken intestine,liver as bait but how successful is the lures which we use now a days?
It is totally depends on anglers that how they represent the lures on water. But if you want using the lure then you have to practice hard to get a success.
6)where can i buy a nice fishing gear total combo set for my requirement.
The site admin (Indianangler : Bops) have lots of nice fishing gear here. So you can PM him for the same, he will provide you the best fishing gear which needed by you at this moment.
7)My budget is not more than 3k.
Please check the tackle shop for the same.
Many advance anglers here and they will give much better answers.
Happy Fishing....