To get back to the home screen just tap on the home button. It is a round physical button on the bottom of the iPad. It has the image of a square on it.
I am not sure if the iPad you bought has the latest OS 7 on it but will assume it does so with that in mind, Download this and it will be your best friend and let you know anything you need to know. This is the other userguide frome Apple for the iPad woth IOS 7. Good luck with your new iPad.