why I cannot conect to the iTunes store with this iPad?

Usually it's because you are not making internet connection via wifi.

Look at iOS Troubleshooting Wi-Fi networks and connections http://support.apple.com/kb/TS1398

iPad: Issues connecting to Wi-Fi networks
http://support.apple.com/kb/ts3304

iOS: Recommended settings for Wi-Fi routers and access points
http://support.apple.com/kb/HT4199

Additional things to try.

Try this first. Turn Off your iPad. Then turn Off (disconnect power cord) the wireless router & then back On. Now boot your iPad. Hopefully it will see the WiFi.

Change the channel on your wireless router. Instructions at http://macintoshhowto.com/advanced/how-to-get-a-good-range-on-your-wireless-netw ork.html

How to Quickly Fix iPad 3 Wi-Fi Reception Problems

http://osxdaily.com/2012/03/21/fix-new-ipad-3-wi-fi-reception-problems/

If none of the above suggestions work, look at this link.

iPad Wi-Fi Problems: Comprehensive List of Fixes

http://appletoolbox.com/2010/04/ipad-wi-fi-problems-comprehensive-list-of-fixes/

Fix iPad Wifi Connection and Signal Issues
http://www.youtube.com/watch?v=uwWtIG5jUxE

 Cheers, Tom 😉

Ok

I'll try it.

Thank you