Aldaar wrote:
OK I'll get an external drive. I just tried to turn on Time Machine but it asks me to create a Time Capsule in Air Port Utility. but Air port Utility can't find a Time Capsule for Time Machine to use . . . but it gives no clue to how to create a Time Capsule! Any clues? Thanks.
As Csound1 has said, you need to have a device you can backup to.
Time Capsule is the name of an Apple manufactured WiFi Router with a built-in backup disk that allows you to backup over your home network. It is managed via the Applications -> Utilities -> Airport Utility. But unless you actually have a Time Capsule product from Apple, that is just Time Machine making assumptions about where you want to backup your data.
When you get an external disk, as soon as you plug it into your Mac, there is a very good chance it will ask you if you want to use it as a Time Machine backup disk.
The advantage of an external disk is they are less expensive than an Apple Time Capsule. The advantage of a Time Capsule is that you do not need to plug it into your Mac, as it will always be available on your home network, when your Macbook is at home.