How is this basic 3D animation template created?
You answered your own question in your tags: use Animation in a 3D package like Blender. 

But TBH your question is too broad to be answerable. To tell you how to make those 3D characters yourself we'd have to explain modelling, rigging, skinning lighting and rendering, not to mention the principles of animation. To give even a basic explanation of any one of those topics would be way beyond the scope of a Stack Exchange anser. 

It's complex and takes a good while to master. If you want to do 3D animation, get a copy of Blender and start watching tutorials, reading books and practising. It's like any other skill set that has to be learned. There is no short cut... apart from buying templates.