What kind of platform are you working with? laptop? desktop? RPi?

You can run Linux on trash hardware. If you have the option, start by installing Linux on something that is not your daily use computer, like an old laptop.

If you can’t do that, then consider getting a second hard drive and installing Linux on that so you don’t have to mess with your primary OS install.

If you can’t do that, then at least prepare a USB drive/DVD installer for your primary OS (presumably Windows) now before you make any changes to your computer. Boot the installer once to make sure it works before you need it.

And before you do anything else back up your important files to an external storage of some type.

It’s extremely useful to have a second working computer to use for doing research and downloading files/installers/recovery tools as needed. Your phone isn’t good enough because you won’t be able to create an OS install drive from it if you need to.