Use a Bootable USB Tool
You have several options depending on your OS
On Windows
Download Rufus:
https://rufus.ie/Open Rufus and follow:
Select your USB device.
Click SELECT and choose the Ubuntu ISO you downloaded.
Leave the partition scheme as MBR for BIOS or GPT for UEFI (most modern PCs use UEFI).
Click START and confirm any prompts.
On macOS
Use Balena Etcher:
https://www.balena.io/etcher/Open Etcher → Select the Ubuntu ISO → Select USB drive → Click Flash!
Boot from USB
Insert the USB drive into the computer you want to install Ubuntu on.
Restart and enter the Boot Menu (usually F12, F2, Esc, or Del).
Select the USB drive to boot.
You can choose Try Ubuntu or Install Ubuntu.
