Hello,
You may find this course helpful: Getting Started with Ansys Mechanical | Ansys Courses
Ansys Workbench helps with the data flow, e.g., Geometry component or Geoemtry cell in a system allows you to either import a geometry or allows you to create a new geometry in Ansys Discovery, SpaceClaim or Designer Modeler; Engineering Data allows you to define the material data needed for the model.
Ansys Mechanical cannot do the above things on its own. So if you try to open Ansys Mechanical, it will open Ansys Workbench with a Mechanical Model Component created by default.
The simulation is actually executed in Ansys Mechanical (not Workbench). Workbench is a more like a tool to manage the data flow between different components and systems.
Is there a reason you don't want to use Ansys Workbench?
You are navigating away from the AIS Discovery experience