Setup
Blender is a free and open-source 3D creation suite, according to their introduction docs.
If you want to read all about its uses and how different industries use the tool, go through the introduction docs.
To boil it down, it can be used throughout almost all stages of making 3D visual media.
Blender is great for 3D modelling, sculpting, texturing, rendering, animation & rigging, VFX, and numerous other things.
It can be highly customized to your liking, even going as far as letting you write your own Python scripts to control it.
Installation
It’s also available on Steam, if you frequently use Steam it is the easiest way to access Blender and stay up to date.
This guide was done in Blender 4.1 and 4.2, however any 4.x Blender version should be alright. Most 3.x versions should be good as well, but several things will be different.
Upon opening, you should be greeted with a similar screen to this:
If you ever need this splash screen back go to the Blender icon in the top left > Splash Screen.