Assuming you had set up your phone to back up your contacts/calendar/photos/videos to Google, those will be auto-restored to your new phone. Your SMS /call logs (unless it is on hangouts) is not auto-backed up/restored.
With Android 6.x, your apps should get reinstalled (assuming you pick that option during the setup of the new phone), and icons placed in the same place on the launcher (assuming you use Google launcher). App data will not be restored for most 3rd party apps (unless they are using the newly introduced Google backup)
The only thing that I worry about is Google Authenticator - you'll need to set that up (if you use it), and scan the account QRs.
You will need to determine what else you need to transfer over.
Summary: most of the things will be auto-restored. There are some exceptions