Are you sure you have a wifi/internet connection?
Saw this on another post.
Applecare Senior Advisor Txx Bxxx (I have his contact info in an email he just sent) just confirmed with me that the problem people are having with the App Store not loading is an apple issue with there servers, ITS NOT YOUR IPAD so don't go restoring it! It's not happening to everyone however but they are looking into it, its really hit or miss.
In the meantime ...........
The Complete Guide to Using the iTunes Store
Can't connect to the iTunes Store
iTunes: Advanced iTunes Store troubleshooting
Best Fixes for ‘Cannot Connect to iTunes Store’ Errors
Try this first - Reset the iPad by holding down on the sleep and home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider - let go of the buttons.
This works for some users. Not sure why.
Go to Settings>General>Date and Time> Set Automatically>Off. Set the date ahead by about a year.Then see if you can connect to the store.