What happen if I restart all the settings in my phone?

You mean a normal restart or a reset? A restart will not do anything but do just that. No data will be lost if that is what you are wondering about. A reset is sometimes necessary when your phone freezes up and is not responding to your input. To reset you hold the sleep/wake button and the home button at the same time. Keep holding until the screen goes black and the white Apple logo appears. when it appears your phone is reset.

Restoring your phone is the part where you will lose your data unless you are using the computer that you always use to update your phone with etc. Also, hopefully you always back your phone up. Hope this explains it a bit. Let us know if you need more help with it. Good Luck.