Rufus is idd the goat, very easy to use, mind that the USB drive will only be a boot drive at that point and not your regular USB drive anymore until you reformat it again, either you can use it to boot from the USB drive everytime (i used to do that with tails) or install the linux OS with a dual boot option (done that with Ubuntu before) if you want to keep your original OS also so whenever launching your pc you choose which OS to load into.