The next thing to secure is the installation files for the macOS version you want to install. And it goes without saying that your USB will have all of its data deleted, so if you need that data, make sure to make a backup before proceeding. Formatting is the only thing you need to take care of when using an old USB. You can use a brand-new drive for this, but any old cheap USB stick will work too.
This is because USB sticks are faster, and if you’re using a newer version of Mac, you’ll have no choice but to use Type C or get an adaptor. If you have the option of choosing, go with a Type C USB rather than a flash drive.
To create a bootable USB on macOS using Install Disk Creator, an empty USB flash drive with a minimum of 8GB storage is required.
