Like video editing software and VFX software, 3D design apps are intensive, so it's best to use a computer with above-average specs across the board: better processor, better GPU, more RAM.
If you just want to have a go, then you should be able to get Blender working on a slightly above average PC (or laptop), such as an Intel Core i5 with a decent graphics card and at least 8GB of RAM.
As soon as you start to want to create and render detailed computer-generated imagery and visual effects, you will need a more powerful machine.
We've hand-picked the best video editing computers, best laptops for video editing, and best computers for engineering students.