Always - always - always back up your photos, videos, personal files to your PC on a regular basis! Don't rely on some app like SmartSwitch (which has proven to me, quite a few times, to be not so smart): plug your phone into the computer with a USB cable and copy/paste the files over. I don't trust "cloud" storage (which is simply someone else's computer drive), either... we have a Synology NAS (Network Attached Storage) here at home that keeps everything archived and under our control.
I back THAT up with external drives. In case the house burns down and takes both of those up in smoke, I have a remote backup NAS at our son's apartment that does encrypted, incremental backups during the night when he's asleep. Am I paranoid? Maybe... to a fault. After 15 years of smartphone use, though, I've learned the importance of redundancy in backup storage. I also want 100% control of our data because Google Drive, OneDrive etc. would data mine & analyze every file to extract as much information as possible; and use that to further build a consumer profile of such extreme, intimate detail that most people would have a heart attack if they actually saw it; and sell that to advertisers who have the money. NO THANK YOU.