Warning
Use a sudo-capable account, keep shell history for audit, and back up critical paths before changing boot, SSH, or package state.
What you will achieve
Build a trusted live USB for installs and recovery — without wiping the wrong disk.
1) Verify ISO checksum before writing
sha256sum ubuntu-24.04-desktop-amd64.iso
2) Write USB from Ubuntu with GNOME Disks or balenaEtcher
Pick the correct target device; this operation erases the USB completely.
3) Boot test in UEFI mode
Use one-time boot menu and confirm the live session starts before relying on the stick for recovery.