Backup and storage before system wipe
At the suggestion of both an Apple phone support technician and an Apple Store Genius Bar employee I met with in person, I have reluctantly agreed to have a system wipe performed on my MacBook to resolve ongoing problems. I probably won't do this for a week or so because I want to explore multiple ways to back up my files. I'll be speaking with someone via phone support about how to save everything to my external backup drive (San Disk G-Drive Armor Lock); the appointment was made by the Genius Bar consultant who probably sensed I was uncomfortable doing this myself. I'm also considering saying a few key, large documents to iCloud Drive. I don't have enough storage for my entire system, and it's not practical to buy that much more, although I might invest in a moderate amount of additional storage. I'm also looking into using at least one more external drive that wouldn't be regularly connected to my laptop like the Armor Lock. It would mainly be an extra storage device for some of my most important files, periodically updated. I'm very nervous about the system wipe and want to take every step I can to protect my data and files. Any recommendations?
MacBook Pro 13″, macOS 15.6