I take it they are teaching from the Windows version of AutoCAD? If so, then please remember they are different programs so there will be differences in available commands and some operations. Both programs are built on top of a unique OS which results in the particular "Window-y-ness" or "Mac-ness" of that particular flavor.
The plus side to this is you are getting good exposure to real working conditions. Going to a new job usually results in using different software (or different version of the same software), different working practices, and there won't always be a subject matter expert to show you exactly what to do.
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If you are going to fly by the seat of your pants, expect friction burns.
Adopt. Adapt. Overcome. Or be overcome.
