Can I reset my iPhone and will all the data will be restored again

Yes, you could restored you data back after successful reset. Before resetting your device don't forget to take back-up.

You can follow the steps below to back-up using iTunes:

If you want your users to be able to back up and restore manually, you could do this via the Documents directory.

1. Contents of the Documents directory are visible to the user in iTunes > iPhone > Apps > File Sharing.
2. You could have a UI control that copies the data to this directory, then the user could use iTunes to save the data to computer's hard drive.
3. The restore would go in the opposite direction.

You can follow the steps below to restore the app with data from iCloud:

1. Make sure your iPhone/iPod/iPad is connected to Wi-Fi and plugged into the charger.
2. Select the option Restore From iCloud Backup.
3. Enter your iCloud account and password.
4. Choose the recent backup you wish to restore to your iOS device.
5. Enter any passwords required when prompted.

If You have back up or synced them to iCloud Yes