CAD Beginner Softwares

You should start with the software that best fits your workflow. If you want to manufacture a plastic part or a product, then you have to learn that software and the software that you will learn for architecture or game character will not be the same.

Personally, I started the journey on AutoCAD [AUTOCAD], (not actually a model) then learned to use SolidWorks which is useful for designing something for manufacturing.

If you want to do some basic 3D printing or a new wooden workbench model, I suggest you start with Fusion 360. It can be used for free for non-commercial use. It will teach you most of the basics (for non-animation / rendering type stuff). You can also use it as a professional

If you are thinking of more 3D art/animation, I would say start with Blender. It's free, great, it's easy to jump in, and has been used professionally.

If you are thinking about building modeling, there is no doubt about learning Revit [AutoDesk Revit].

If you're looking for fun algorithmic designs, the Rhino with Grasshopper flame will probably come in handy.