My WiFi is grayed out and I can not turn it in

This usually indicates a hardware issue requiring you to take it to Apple or an authorized repair center to get fixed. It may also be a software issue, for which you can try the steps below, but I want to set the expectation that it is probably hardware related.

Try restarting your phone.

Try going to Settings > General > Reset > Reset Network Settings.

If that doesn't work, try restoring: http://support.apple.com/kb/HT1414

Note that you need to make a backup before restoring if you do not want to lose data.

Read here => If your iPhone, iPad, or iPod touch won’t connect to a Wi-Fi network - Apple Support