Chorderator Chord Generator
One really should just learn theory, because once this stuff is learned and memorized one understands it's not all that tuff. Plus it's just way faster to have all this stuff at your brain's fingertips!
But in the beginning I learned by hand shapes and diagrams and used them until I learned the info. Comes a time it becomes automatic and one doesn't have to think about it anymore. The faster you learn theory, the faster you imbed it.
IMO the fun way to learn theory is in a class setting, where a lot of people are discussing and asking questions. People ask questions you may not have thought to ask, or may have another approach to a concept you've been struggling to grasp. Or even ask questions you were too shy to ask for fear of looking foolish. Never feel asking questions is foolish!
Of course these comments are MHO, 2¢, ymmv, etc. Enjoy!