You need server environment to run WordPress on.
Most people get a hosting provider and install WordPress there, but if you just want to see what you can do with WordPress on your computer, you’ll need to install a local server environment: https://make.www.ads-software.com/core/handbook/tutorials/installing-a-local-server/
If you’re installing on a hosting provider, you don’t need anything installed on your computer to use WordPress besides a web browser.
I strongly recommend reading this first: https://codex.www.ads-software.com/New_To_WordPress_-_Where_to_Start
