how do I back up my MacBook without buying a usb , I need to send my MacBook off to be fixed so that's why I need to back it up first , thanks

Hi spillerz04,

If your Mac can still start up normally, your best option is to purchase an external hard drive from a local technology store, and use it to back up with Time Machine on your Mac. The external drive should have at least twice the storage capacity of the data being stored on your Mac. I would recommend that the external drive be at least 1 TB (1 terabyte, aka 1000 GB/gigabytes) large.

There are other backup solutions available (such as Backblaze), but they either require an external drive, or upload your data through the network (and maybe the Internet), which can take a long time to complete. Please note that iCloud is not a supported backup solution for Macs.

As mentioned by MrHoffman, it is important to back up your Mac regularly, and before disaster strikes.

Don’t bother backing up. Seriously. Your data clearly has no value to you, whether the data gets wiped or lost or stolen or dunked or dropped doesn’t matter, and since you don’t ever need that data back, so just send it in. (Seems harsh? Why do I write that? Because you have no backups now. That means you believe your data worth little or nothing to you, or can be easily replaced.)

Now if your data has value, then you’ll be using a USB-connected storage device (hard disk drives are typical, as they’re bIg and ~cheap) and Time Machine, or using network-attached storage with Time Machine support (less cheap, but can be shared by multiple Macs), or (maybe) iCloud with files and documents enabled. The iCloud storage is not a backup, and will be limited by the amount of iCloud storage you have rented and the speed of your ISP network link, and it is not a complete backup.

Add your Desktop and Documents files to iCloud Drive - Apple Support

Now if your Mac is bricked and cannot get a back up, then it’s too late to get a backup. You might get data recovered by a recovery firm (expensive, whether or not any data can be recovered), or the repairs might preserve the data, but the time to get a backup is prior to the theft or loss or dropping or dunking or damage or whatever happened here.

create a bootable external hard drive of your cloned system. Using your machines settings and specialized software.

https://www.imore.com/how-to-clone-your-mac

ive not done it but it says you can attach the hd or suppose a ssd to another mac and continue working steps are explained.

if you cant save to the cloned device you should get a usb thumb until it returns. Other Blu-ray disk of different flavors dual sided etc. Gl