Backing Up My System

[jazzyjj]

Hi everybody. Yesterday I scheduled a Genius Bar appointment for Monday afternoon at one of the Apple stores in my area. I've been having a memory issue on my MacBook Air for a little while, and we think we know what's causing it but we want someone at the Genius Bar to take a look. The confirmation email I got yesterday said for me to back up my system prior to the appointment, and I'm wondering which method is preferred here. I was originally going to purchase an external hard drive, but then my father suggested I'd be better off using iCloud. A tutor and I recently tried to set up iCloud on my MacBook but ran into a bit of difficulty. I use Apple's on-board screen reader and it seems to work pretty well with iCloud, but we couldn't quite figure out how to set everything up. Another suggestion my tutor made is Google Drive, and he said some of his coworkers at school use it and like it. When he and I checked the amount of space for iCloud, we found out that it starts out at 5 gb which he said would probably not be enough for everything I have on here. I checked on Apple's support site and think I saw something about using a thumbdrive. I have 2 of those, but they both contain mp3 files. So would a cloud-based service be necessary or is Time Machine good enough? That also seems pretty accessible with the screen reader on here. Thanks in advance for anyone's assistance.