Is there any mechanical engineers? What you would wish to know when you were starting learning? What skills and topics you consider the most useful in mechanical engineering?
What is the fastest way to learn mechanical engineering in the nowadays when 3d printers are avaliable to be able to design and make custom clocks, engines, generators?
Know the old school basics of design.
Limits and fits, tolerance stacks, good drawing practice, know which dimensions are important in your design and which are not and tolerance accordingly, etc
Also, know how stuff is made; how mills and lathes cut material, what are your machine capabilities. The number of, unrealistic tolerances and impossible geometries I see from new engineers is astounding.
Also a good understanding of statistical analysis tools for optimising assembly designs.
Sorry if these seem boring. But they the foundation of mechanical design and appear to be seriously lacking in new engineers.