A Live USB will let you run an operating system off of a USB drive, so you can try a operating system without a partition, or carry a favorite one with you, or have an emergency backup in case your computer crashes. It's a beginner friendly tutorial, and assumes you know the basics of computer navigation, but if you are familiar with computers, you should be able to follow the abridged version I have at the second to last step. There are a lot of different softwares out there to do this, so I've tried out a bunch and I'm bringing two good ones to you. I will also be showing you some notable Linux operating systems you can get for free.
Are you thinking of the best Linux for kids? If no, you should start thinking now. Linux is everywhere.