Design Accelerators are not perfect but can provide a quick validation of what you design, where calculations matter. I used it in the past mostly for shaft generation and bolted connection strength checks, and you can always modify on what the tools give you as resulting geometry. I know for sure that the gear teeth profiles produced in gear generators are not perfect for fabrication, but going through the motions of using the calculators there would at least provide you a quick start on size and function that can be trusted.
Honestly, there is no easy way of teaching some of these. It actually takes a course load or sequence of long tutorials to explore and learn most of these. Pick one at a time as you need them.
https://knowledge.autodesk.com/support/inventor/learn-explore/caas/CloudHelp/cloudhelp/2022/ENU/Inve...
