To perform a clean install, you will need a USB flash drive with at least 16 GB of space. Format the Drive Disk Utility to format your USB drive as Mac OS Extended (Journaled) GUID Partition Map Terminal Command
While macOS High Sierra is an older operating system, it is still possible to download and install version 10.13.6 for recovery or legacy support purposes. For the most secure and reliable experience, it is recommended to download the installer directly through official channels. Official Download Method download+macos+high+sierra+10136+dmg+mac+install