I can't connect my iPhone with laptop and can't update my iPhone?

Hello: dear I'm using iPhone 3GS and it worked every thing well few months ago, but now AppStore and others can't download even free apps then I tried to update my iPhone through iTunes in my laptop but unfortunately when I connect it through USB cable, there's nothing happen even it can't be charged. One thing more that when I off my iPhone which is already connect with laptop it is on automatically but did not charging or connecting. Please help me with complet information I need to update my iPhone and also download apps.

I suggest restoring it back to factory settings.
This can be done by holding down the home button and the sleep/wake button for 10 seconds then release the sleep/wake button until the apple logo appears.