

You also won’t find it in the App Store app under Purchased. If you already installed High Sierra, you won’t find the installer app in your Applications folder. If not, just do a search for “High Sierra.” Click on it to go to the High Sierra page. Go to the Featured section of the App Store, and you may see High Sierra appear at the top. If you launch the App Store app and look for it in the Updates section, you won’t find it. It’s not available as an update, so if you run Software Update (Apple menu > About This Mac > Software Update), you won’t find it. You’ll find High Sierra in the App Store. Get the macOS High Sierra installer software

When creating the boot drive, the storage device is reformatted, so there’s no need to format the drive beforehand. If you have a USB-C storage device, then you don’t need to get the adapter. This will allow you to connect a storage device that uses a USB type-A connector. If you have a 2015 or newer MacBook or a 2016 or newer MacBook Pro, you may need Apple’s USB to USB-C adapter. To connect a USB device with a type-A connector to a MacBook or MacBook Pro with USB-C, you need the USB to USB-C adatper.
