TinkerCAD costs $19 per month for the Personal edition and $100/month for the Startup edition. I'd buy a basic CAD package rather than "rent" one month to month. Three-dimensional printers might appeal to more people at a lower cost, but as the cost goes down I expect more small companies to offer 3-D printing services--perhaps even the UPS Store or local Kinkos-Fedex store could make my prototypes.
I no longer make my own printed-circuit boards because I can get a 2-day turnaround from local shops that welcome small orders. And some PCB quick-turn companies also provide the schematic-capture and board-layout tools for free. Watch the same thing happen with 3-D printing.
As manufacturers add new technologies to their products, designing for compliance becomes more difficult. Prepare for the certification testing process. Otherwise, you increase the risk of discovering a safety issue after a product leaves the assembly line. That will cause significant time-to-market delays, be much costlier to fix, and damage your brand in the eyes of customers.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies.
You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived.
So if you can't attend live, attend at your convenience.