Welcome to Android Central! Rooting is not for novices, so I would think twice before considering this. The forums at XDA-Developers.com is a good resource for rooting, but it's not a simple process. See this thread:
https://forum.xda-developers.com/ver...mware-t3693790
Are you sure you weren't using Google Photos auto-backup, which would've automatically backed up your photos and videos to your Google Photos in the cloud? Go to photos.google.com on your computer browser and see if any of them are there.