AutoCAD is the most popular software used my professionals with ME degree. If you are interested in pursuing your career as a Design Engineering, you can learn one of the design software like AutoCAD, CATIA, PTC Creo, SolidWorks, etc. In case you are interesting in analysis / simulation, you can go through some short courses in analysis software like Ansys, MoldFlow, Fluent, etc.

Good Luck.