I only have a theory about invention, but I haven't actually done it. Can I apply for a patent for invention or utility model? Will you be required to check the physical objects during the application

I only have a theory about invention, but I haven't actually done it. Can I apply for a patent for invention or utility model? Will you be required to check the physical objects during the application process? or You don't need physical objects, but you need to state the principle clearly.

The utility model needs drawings, and only protects products, methods, formulas, etc.

Inventions can.

The invention process includes two steps: publication and actual review, which usually takes two or three years.

The utility model is only examined once, and it is generally authorized for more than half a year.