Linux

You need a software like rufus or etcher for windows. Run the software as admin, select your drive (be careful to select the right one. It will be wiped in the process), select you iso file of linux mint and confirm. The software will create a bootable usb drive. Plug it into you pc and reboot. Now the process ist depending on your computer. Some will boot right into the live usb others will boot back into your normal hard drive. If later one is the case, you need to enter your boot menu via one of the function keys. Which one depends on your mainboard.

If you still have questions, feel free to ask. And have fun with Linux :D

look up rufus or ventoy and start from there

Plenty of tutorials out there, you can have a google for one that you like. It's pretty simple though, just download a .iso of the distro you want to try, and then flash it to a thumb drive using, I'd suggest, Rufus. Balena Etcher is another good option.

Use Balena Etcher to "burn" (the correct term is flash) the iso on the usb

I'd suggest checking out the official installation instructions linked at the top of the mint homepage. They're pretty good.

here you go

Perhaps this page in Mint documentation may help https://linuxmint-installation-guide.readthedocs.io/en/latest/burn.html#how-to-make-a-bootable-usb-stick

The following video is more advanced but covers Ventoy which lets you have a bootable disk that you can copy ISO files onto. You will then have an USB with multiple distributions that you can pick and choose between at boot time. https://www.youtube.com/watch?v=10L8aCY3VBs

Are you in windows or Linux?

https://rufus.ie/en/