Suppose an enterprising young fellow wants to get his feet wet in 3d design and modeling for personal/commercial use. Is there a school, education path, or certification in CAD or any of the modeling software that I should pursue? At the moment, I want to learn how to create my own designs, but I have no background in CAD and my only 3d design experience is from graphic design (i.e. GIMP/photoshop) and pottery/sculpting.

Right now, I want to get started designing and printing my own models, with the possibility of selling them in the future. I have built (the printer) and printed basic models with my prusa i3v, but want to get into customizing and building 3d models from scratch. Certification cost isn't a factor, but I am not necessarily looking to commit to a full blown engineering/design degree. I have a BA in computer information systems, and I think it may be a bridge too far to transition into engineering. I am not opposed to open source software and experimentation, but it has been my experience that a formal education gets results much quicker. I am open to all recommendations, thanks!