Hi Somesh.
Sorry to hear your first time experience with Arduino has not been so good. Is it possible to provide some screenshots of the error messages in the IDE so we can help you?
One question springs to mind. Is the Arduino Leonardo connected to the computer via a usb hub. If so, until you find the problem, make sure you connect directly to the PC. This goes for any Arduino problem troubleshooting.
Finally see this post Arduino Forum
Regards,
Dale