By default, your USB drive is very likely password-free, which means anybody with the stick can plug it into their own computer and browse your files. If you store financial information or security ...

then restarting the computer and choosing to boot from the USB stick. How this is done varies, but it usually involves pressing a key to choose a boot device while the computer's starting up ...

On Ubuntu, hit your Super key (formerly the Windows key ... Startup Disk Creator should automatically detect your USB stick, but if you happen to have more than one inserted, ensure it's picked ...