Can I get my informations back when I change my phone

Are you changing from one iPhone to another? If so, you should be able to transfer your phone's data from either a backup to iCloud or to a computer running iTunes/Finder.

To get an idea on how this works, take a look at these support articles:

• Set up your iPhone, iPad, or iPod touch - Apple Support
• Use iTunes or the Finder to transfer data from your previous iOS device to your new iPhone, iPad, or iPod touch - Apple Support