Nikhil Narale
Ansys Employee

Step 1: This should be a good starting point for you to learn how to prepare geometry for CFD: Geometry Prep for CFD using Ansys Discovery | Ansys Courses

Step 2: Once you have the CAD ready, you can learn how to create grid (mesh) using the Ansys Fluent Meshing Watertight Geometry Workflow: Mesh Generation using Ansys Fluent Meshing | Ansys Courses