What each tool does
AutoCAD is a general drafting tool. You draw lines, arcs and text to make 2D plans, elevations and details. It's still used on most site and consultancy drawings.
Revit is a BIM tool. You model walls, floors and roofs as real building parts, and the drawings and schedules come from that model.
Start with AutoCAD if…
You're new to design software, you want to start drafting soon, or the firms near you mostly send and receive 2D DWG drawings.
Start with Revit if…
You already know drafting basics, you want BIM roles, or you plan to work with larger architecture firms and projects.
Our suggestion
Most students do best learning AutoCAD first and then Revit. Drafting basics make it much easier to understand the views and sheets in a model.