You can restore a different backup as long as the backup does exist. You would have to erase your phone in the settings and start over again. You can select the backup that you want when you get to the point in the set up where you can restore from a backup. The blurb below is copied from the erase iPhone link that I posted.
Erase iPhone - Apple Support
Use Settings to erase iPhone
- Go to Settings
> General > Transfer or Reset iPhone. - Do one of the following:
- Prepare your content and settings to transfer to a new iPhone: Tap Get Started, then follow the onscreen instructions. When you finish, return to Settings > General > Transfer or Reset iPhone, then tap Erase All Content and Settings.
- Erase all of your data from iPhone: Tap Erase All Content and Settings.
Note that if you already backed up the new phone, the old backup that you want to restore from may no longer exist.
EDIT - it took me a while to type my response so I apologize to my friend, elcpu who already answered the question.